CN116476012A

CN116476012A - Electric tool

Info

Publication number: CN116476012A
Application number: CN202310660287.XA
Authority: CN
Inventors: 陈杰
Original assignee: Suzhou Duobei Tool Technology Co ltd
Current assignee: Suzhou Duobei Tool Technology Co ltd
Priority date: 2023-06-06
Filing date: 2023-06-06
Publication date: 2023-07-25

Abstract

The invention discloses an electric tool, which comprises an output shaft, an impact mechanism and a transmission mechanism, wherein the transmission mechanism is installed between the output shaft and the impact mechanism in a linkage way and is used for transmitting torque generated by the impact mechanism to the output shaft, and the transmission mechanism comprises: the connecting piece is driven by the impact mechanism and can axially rotate around the connecting piece; the reduction gear set is arranged between the output shaft and the connecting piece in a linkage way, the reduction gear set is driven by the connecting piece, and the reduction gear can drive the output shaft to rotate around the axial direction of the reduction gear set; wherein the rotational speed of the connecting piece is greater than the rotational speed of the output shaft.

Description

Electric tool

Technical Field

The present invention relates to power tools, and more particularly to a power tool with an impact structure.

Background

In the electric tools, the impact wrench type tools utilize an impact structure to continuously impact a wrench head (an output shaft) to generate locking torsion. The output torque of the impact wrench is related to the rotation speed of the impact structure and the weight size of the impact block in the impact mechanism, the rotation speed of the impact structure can be limited by the rotation speed of the motor, and the abrasion of parts in the impact structure can be increased when the rotation speed of the impact structure is increased, so that the impact wrench needs to be provided with a large impact block when the rotation speed of the impact structure is limited, the structure of the impact wrench is increased when the impact block is increased, and the impact wrench releases a large torque when the structure is small, so that the impact wrench is provided with a technical problem which needs to be solved at present.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Disclosure of Invention

The present invention aims to provide an electric tool capable of increasing torque of an output shaft in the electric tool.

To achieve the above object, an embodiment of the present invention provides an electric tool including an output shaft, an impact mechanism, and a transmission mechanism mounted between the output shaft and the impact mechanism in a linkage manner, for transmitting torque generated by the impact mechanism to the output shaft, the transmission mechanism including:

the connecting piece is driven by the impact mechanism and can axially rotate around the connecting piece;

the reduction gear set is arranged between the output shaft and the connecting piece in a linkage way, the reduction gear set is driven by the connecting piece, and the reduction gear can drive the output shaft to rotate around the axial direction of the reduction gear set;

wherein the rotational speed of the connecting piece is greater than the rotational speed of the output shaft.

In one or more embodiments of the invention, the ratio of the rotational speed of the connection to the rotational speed of the output shaft is greater than or equal to 2.

In one or more embodiments of the invention, the ratio of the rotational speed of the connection to the rotational speed of the output shaft is 2 to 4.

In one or more embodiments of the invention, the reduction gear set includes a drivingly connected input gear and output member, the output member being connected to the output shaft, the input gear being connected to the connecting member.

In one or more embodiments of the present invention, the reduction gear set is a first planetary gear train including the input gear, a plurality of first planetary gears surrounding and engaging the input gear, a first ring gear engaged with the plurality of first planetary gears, and the output carrying the plurality of first planetary gears.

In one or more embodiments of the present invention, the reduction gear set is a fixed-axis gear train, the output member is a gear, the fixed-axis gear train includes an input gear, a plurality of fixed gears surrounding and engaging the input gear, the output member engaging with the plurality of fixed gears, and a carrier carrying the plurality of fixed gears, the fixed gears include a first gear portion and a second gear portion coaxially disposed, the first gear portion is engaged with the input gear, and the second gear portion is engaged with the output member.

In one or more embodiments of the present invention, the output member includes an annular gear portion and a connection portion, the connection portion has a rotation stopping hole, the output shaft and the rotation stopping hole are spliced to form a rotation stopping structure, and the annular gear portion is meshed with the input gear.

In one or more embodiments of the invention, the input gear is integrally connected with the connecting member.

In one or more embodiments of the invention, the impact mechanism has a drive shaft, and the end of the connecting piece facing the impact mechanism has a first connecting hole, and the drive shaft is connected with the first connecting hole in an inserting way.

In one or more embodiments of the present invention, the inner wall of the first connecting hole in the axial direction is clamped with the driving shaft to mount balls.

Compared with the prior art, the electric tool according to the embodiment of the invention has the advantage that the torque of the output shaft is increased by adding the transmission mechanism between the impact mechanism and the output shaft. Specifically, the impact mechanism impacts the connecting piece to enable the connecting piece to rotate, the connecting piece is in transmission connection with the output shaft through the reduction gear set, and torque generated by the impact mechanism impacting the connecting piece is transmitted to the output shaft after the torque is increased through the reduction gear set through the principle of reduction and torque increase of the reduction gear set, so that the torque of the output shaft is increased.

Drawings

FIG. 1 is a schematic view of a power tool according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a power tool according to an embodiment of the invention;

FIG. 3 is an exploded view of a portion of the components of a power tool according to one embodiment of the present invention;

FIG. 4 is an exploded view of an output shaft, impact mechanism, and transmission mechanism according to an embodiment of the present invention;

FIG. 5 is an exploded view of an output shaft, impact mechanism, and transmission mechanism according to another embodiment of the present invention;

FIG. 6 is a schematic partial cross-sectional view of a power tool according to another embodiment of the invention;

FIG. 7 is an exploded view of an output shaft, impact mechanism, and transmission mechanism according to an embodiment of the present invention;

fig. 8 is a schematic partial cross-sectional view of a power tool according to an embodiment of the invention.

The main reference numerals illustrate:

1. an output shaft; 11. a rotation stopping part; 111. a first rotation stopping surface; 2. an impact mechanism; 21. a drive shaft; 3. a transmission mechanism; 31. a connecting piece; 311. a first connection hole; 312. a protrusion; 32. a reduction gear set; 321. an input gear; 322. an output member; 3221. an inner gear ring part; 3222. a connection part; 3223. a rotation stopping hole; 32231. a second rotation stopping surface; 323. a first planet; 324. a first ring gear; 325. a fixed gear; 3251. a first gear portion; 3252. a second gear portion; 326. a gear frame; 3261. a fixing frame; 32611. a second connection hole; 3262. an end plate; 32621. a third connection hole; 3263. a fixed shaft; 327. a positioning plate; 3271. a fourth connection hole; 4. a housing; 41. a housing; 42. a gearbox rear housing; 43. a gearbox front cover; 5. a motor; 51. a motor shaft; 6. a second planetary gear train; 61. a second planet wheel; 62. a second ring gear; 63. a pin; 7. and (3) rolling balls.

Detailed Description

The following detailed description of embodiments of the invention is, therefore, to be taken in conjunction with the accompanying drawings, and it is to be understood that the scope of the invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the term "comprise" or variations thereof such as "comprises" or "comprising", etc. will be understood to include the stated element or component without excluding other elements or components.

As shown in fig. 1 to 3, an electric tool according to a preferred embodiment of the present invention includes an output shaft 1, an impact mechanism 2, and a transmission mechanism 3, the transmission mechanism 3 being mounted in linkage between the output shaft 1 and the impact mechanism 2 for transmitting torque generated by the impact mechanism 2 to the output shaft 1, the transmission mechanism 3 including a connecting member 31 and a reduction gear set 32; the connecting piece 31 is driven by the impact mechanism 2, and the connecting piece 31 can axially rotate around the connecting piece; a reduction gear set 32, which is mounted between the output shaft 1 and the connecting piece 31 in a linkage manner, wherein the reduction gear set 32 is driven by the connecting piece 31, and the reduction gear can drive the output shaft 1 to rotate around the axial direction of the reduction gear set; wherein the rotational speed of the coupling member 31 is greater than the rotational speed of the output shaft 1.

It will be appreciated that the power tool of the present invention may be an impact wrench or the like. The speed reduction gear set 32 in the transmission mechanism 3 not only can reduce the rotating speed, but also can realize the improvement of the torque. The impact mechanism 2 may comprise an impact block, and the driving of the connecting piece 31 by the impact mechanism 2 may be understood as: the impact block can drive the connecting piece 31 to rotate along the circumferential direction of the connecting piece 31; or, the impact block forms a circumferential striking action on the connecting member 31 along the circumferential direction of the connecting member 31 to drive the connecting member 31 to rotate.

Taking an impact wrench as an example, the process of screwing the workpiece by the impact wrench can be divided into two stages; the first stage may be considered as the workpiece rotating rapidly with the impact wrench, where the impact mechanism 2 does not produce a circumferential striking motion. The second stage is a workpiece tightening stage, namely, the workpiece rotation speed is greatly reduced, at this time, the impact mechanism 2 forms a circumferential striking action, and at this time, the workpiece rotation is slow and the rotation is slower along with the increase of the tightening action, at this time, the influence of the reduction gear set 32 on the rotation speed is negligible, so that the reduction gear set 32 mainly plays a role of increasing the torque of the output shaft 1 and screwing the workpiece as much as possible.

Compared with the impact wrench in the prior art, the electric tool of the invention can increase the torque of the output shaft 1 without changing the size of the striking block in the impact mechanism 2 and the power of the motor 5, and is beneficial to the miniaturization of the electric tool because the transmission mechanism 3 is added between the output shaft 1 and the impact mechanism 2 only along the axial direction of the electric tool, and the radial size of the electric tool is increased less.

As shown in fig. 1 to 3, in a specific embodiment, the electric tool of the present invention includes a housing 4, and a motor 5 and a plurality of second planetary gear trains 6 mounted in the housing 4. The second planetary gear train 6 plays a role of connecting the motor 5 and the impact mechanism 2 in a transmission manner, namely, the power of the motor 5 is transmitted to the impact mechanism 2, so that the impact mechanism 2 can generate striking force and drive the output shaft 1 to rotate. Specifically, the second planetary gear train 6 plays a role in reducing speed and increasing torque, that is, the torque output by the motor 5 is transmitted to the impact mechanism 2 after the second planetary gear train 6 plays a role in reducing speed and increasing torque. The motor 5 has a motor shaft 51 as a power output member, and the motor shaft 51 is connected to the second planetary gear train 6. The housing 4 comprises a housing 41, a gearbox rear casing 42 and a gearbox front cover 43 connected.

Specifically, as shown in fig. 3, the second planetary gear train 6 may include a sun gear (not shown in the drawing) as an input member, a plurality of second planetary gears 61 surrounding and engaging the sun gear, a second ring gear 62 engaged with the plurality of second planetary gears 61, a plurality of pins 63 carrying the plurality of planetary gears, the pins 63 being in one-to-one correspondence with the second planetary gears 61, the pins 63 being connected with the drive shaft 21 of the impact mechanism 2, the second planetary gears 61 being mounted on the pins 63, the second planetary gears 61 being rotatably connected with the drive shaft 21 through the pins 63; the second annular gear 62 is fixedly mounted on the casing 4; the sun gear can be directly sleeved on the motor shaft 51, and the sun gear is in interference fit with the motor shaft 51. In other embodiments, the sun gear may be integrally formed with the motor shaft 51.

In other embodiments, the motor 5 and the impact mechanism 2 may be drivingly connected by other gear assemblies.

It should be noted that if the reduction gear set 32 of the present invention is placed between the motor 5 and the impact mechanism 2, the action of the reduction gear set 32 and the second planetary gear train 6 can be regarded as similar, since there are several second planetary gear trains 6 between the motor 5 and the impact mechanism 2, unlike the same effect achieved by increasing the number of second planetary gear trains 6, that is, the effect of increasing the torque by decelerating. But is set so that the rotation speed of the striking block on the impact mechanism 2 is too low, i.e., the impact mechanism 2 may not be able to perform the circumferential striking action. Therefore, the invention sets the reduction gear set 32 between the impact mechanism 2 and the output shaft 1, that is, the rotation speed of the striking block in the impact mechanism 2 is enough to realize the circumferential striking action, so that the impact mechanism 2 can output torque outwards, and the reduction gear set 32 increases the torque which is formed by the impact mechanism 2 and is output.

In one embodiment, the ratio of the rotational speed of the connecting member 31 to the rotational speed of the output shaft 1 is greater than or equal to 2. By the arrangement, the torque can be obviously increased; and the larger the ratio of the rotational speed of the connecting member 31 to the rotational speed of the output shaft 1, the larger the amount of increase in torque.

Preferably, the ratio of the rotational speed of the connecting member 31 to the rotational speed of the output shaft 1 is 2 to 4. In the process of reducing and increasing torque, the larger the ratio of the rotational speed of the connecting member 31 to the rotational speed of the output shaft 1, the larger the torque increase amount, but the heavier the load on each component in the reduction gear set 32 and each component in the electric tool, that is, the higher the requirements on the strength and stability of each component. Therefore, the ratio of the rotational speed of the connecting member 31 to the rotational speed of the output shaft 1 is set to 2 to 4, which is a reasonable range, and the torque increasing amount can be more ideal, and the requirements of the strength and the stability of each component can be matched, and the cost and the service life of each component can be also realized.

The reduction gear set 32 comprises a drivingly connected input gear 321 and an output member 322, the output member 322 being connected to the output shaft 1, the input gear 321 being connected to the connecting member 31. Wherein the input gear 321 and the output member 322 may be directly in driving connection, for example, when the output member 322 is a gear, it is meshed with the input gear 321; the input gear 321 and the output 322 may also be indirectly connected, i.e. connected by other components, including at least one gear component.

In one embodiment, as shown in fig. 2-4, the reduction gear set 32 is a first planetary gear train, which includes an input gear 321, a plurality of first planetary gears 323 surrounding and engaging the input gear 321, a first ring gear 324 engaged with the plurality of first planetary gears 323, and an output member 322 carrying the plurality of first planetary gears 323.

It will be appreciated that in the above embodiments, the input gear 321 corresponds to the sun gear member of the first planetary gear set, i.e., as the power or torque input member of the reduction gear set 32; the input gear 321 is connected to the connecting member 31 and is rotatable synchronously with the connecting member 31. The output member 322 may act as a carrier in a first planetary gear train, with the output shaft 1 being connected to the output member 322 and being rotatable synchronously with the output member 322.

Wherein, the output piece 322 is fixedly connected with the output shaft 1; the fixed connection can be in the modes of integrated connection, welding, interference fit, clamping, cementing, riveting and the like.

In another embodiment, as shown in fig. 5 and 6, the reduction gear set 32 is a fixed-axis gear train, the output member 322 is a gear, and the fixed-axis gear train includes an input gear 321, a plurality of fixed gears 325 surrounding and engaging the input gear 321, the output member 322 engaged with the plurality of fixed gears 325, and a carrier 326 carrying the plurality of fixed gears 325; the fixed gear 325 may be a double gear, and the fixed gear 325 includes a first gear portion 3251 and a second gear portion 3252 coaxially disposed, the first gear portion 3251 being engaged with the input gear 321, and the second gear portion 3252 being engaged with the output member 322. The outer diameters of the first gear portion 3251 and the second gear portion 3252 are different, and the reduction gear set 32 serves to reduce the speed and increase the torque (increase the torque) by designing the meshing relationship and the gear ratio among the output member 322, the first gear portion 3251, the second gear portion 3252, and the input gear 321.

It can be appreciated that the gear rack 326 includes a fixing frame 3261, an end plate 3262 and a plurality of fixing shafts 3263, and two axial ends of the fixing shafts 3263 are respectively mounted on the fixing frame 3261 and the end plate 3262; the fixed frame 3261 is provided with a second connecting hole 32611 extending along the axial direction, the output piece 322 and/or the output shaft 1 is/are partially penetrated into the second connecting hole 32611, and the output piece 322 and/or the output shaft 1 is/are partially rotatably connected with the second connecting hole 32611; the end plate 3262 is provided with a third connection hole 32621, the connecting element 31 is connected to the third connection hole 32621 in a penetrating manner, and the connecting element 31 is rotatably connected to the third connection hole 32621. The fixed frame 3261 is fixedly installed in the casing 4, and the fixed frame 3261 and the casing 4 are relatively non-rotatable in an operating state of the power tool, that is, the fixed gear 325 rotates only and does not revolve around the input gear 321.

In yet another embodiment, as shown in fig. 7 and 8, the output member 322 includes an annular gear portion 3221 and a connecting portion 3222, the connecting portion 3222 has a rotation stopping hole 3223, the output shaft 1 and the rotation stopping hole 3223 are spliced to form a rotation stopping structure, and the annular gear portion 3221 is meshed with the input gear 321.

It can be appreciated that the output shaft 1 includes a rotation stopping portion 11, and the rotation stopping portion 11 is spliced with the rotation stopping hole 3223 to form a rotation stopping structure. The rotation stopping structure mainly functions to rotate the connection portion 3222 and the rotation stopping portion 11 together, even if the output member 322 rotates together with the output shaft 1.

Preferably, the rotation stopping portion 11 has at least one first rotation stopping surface 111, at least one second rotation stopping surface 32231 on an inner wall of the rotation stopping hole 3223, and the first rotation stopping surface 111 and the second rotation stopping surface 32231 are opposite to each other to form a rotation stopping structure. During the rotation of the connection portion 3222 and the rotation stopping hole 3223, the second rotation stopping surface 32231 at least partially abuts against the first rotation stopping surface 111, so as to generate a force pushing the first rotation stopping surface 111, and further generate a force driving the rotation stopping portion 11 to rotate along the axial direction thereof, so that the rotation stopping portion 11 and the rotation stopping hole 3223 (i.e. the connection portion 3222) synchronously rotate.

In the embodiment shown in fig. 7 and 8, the rotation stopping portion 11 is in a rod shape, the first rotation stopping surface 111 is disposed on the outer peripheral surface thereof, the rotation stopping portion 11 may include a plurality of first rotation stopping surfaces 111 disposed along the circumferential direction, the inner wall of the rotation stopping hole 3223 is correspondingly disposed with a plurality of second rotation stopping surfaces 32231 along the circumferential direction, and the first rotation stopping surfaces 111 and the second rotation stopping surfaces 32231 are in one-to-one correspondence.

Further, the rotation stop portion 11 is interference fit with the rotation stop hole 3223. By this arrangement, the connection between the rotation stop portion 11 and the rotation stop hole 3223 can be made more stable. Of course, in other embodiments, the rotation stopping portion 11 and the rotation stopping hole 3223 may not be in interference fit, so long as the rotation stopping hole 3223 can play a role of driving the rotation stopping portion 11 to rotate synchronously.

In the embodiment shown in fig. 7 and 8, the reduction gear set 32 further includes a positioning disc 327, the positioning disc 327 is fixedly mounted in the casing 4, the positioning disc 327 is provided with a fourth connecting hole 3271 extending along the axial direction of the positioning disc 327, the connecting piece 31 is inserted into the fourth connecting hole 3271, and the connecting piece 31 is rotationally connected with the fourth connecting hole 3271, so as to play a role in positioning and mounting the connecting piece 31. The spacer 327 may have a plurality of lightening holes thereon to reduce the weight of the spacer 327.

In any of the three embodiments shown in fig. 2 to 8, the input gear 321 and the connecting member 31 are fixedly connected, and the fixed connection may be integrally formed, welded, interference fit, clamped, glued, riveted, or the like.

Preferably, the input gear 321 is integrally connected to the connecting member 31. This arrangement can reduce the number of parts and improve the connection strength of the input gear 321 and the connection member 31.

In the embodiment shown in any of fig. 2 to 8, the impact mechanism 2 has a drive shaft 21, and the end of the connecting piece 31 facing the impact mechanism 2 has a first connecting hole 311, and the drive shaft 21 is inserted into the first connecting hole 311. This arrangement serves to axially locate the connector 31.

Further, the ball 7 is held between the inner wall of the first connecting hole 311 in the axial direction and the drive shaft 21. By utilizing the rolling motion mode of the balls 7, the friction mode between the inner wall of the axial direction of the first connecting hole 311 and the end surface of the driving shaft 21 is changed from sliding friction to rolling friction, so that the abrasion between the driving shaft 21 and the connecting piece 31 is reduced, and the service lives of the two parts are prolonged.

In the embodiment shown in any one of fig. 2 to 8, the outer peripheral surface of the end portion of the connecting member 31 facing the impact mechanism 2 is provided with a protrusion 312, and when the striking block of the impact mechanism 2 rotates in the circumferential direction, the striking block abuts against the protrusion 312 and drives the protrusion 312 to rotate in the circumferential direction, that is, the impact mechanism 2 drives the connecting member 31 to rotate in the circumferential direction. Wherein rotation in the circumferential direction may also be considered as axial rotation about itself.

In either embodiment as shown in fig. 4 or 5, the output shaft 1 and the motor shaft 51 are on the same axis, so that they operate more stably and are smaller in radial dimension.

The foregoing descriptions of specific exemplary embodiments of the present invention are presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application to thereby enable one skilled in the art to make and utilize the invention in various exemplary embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. The utility model provides an electric tool, its characterized in that includes output shaft, impact mechanism and drive mechanism, drive mechanism linkage install in between output shaft and the impact mechanism for with the moment of torsion that impact mechanism produced is transmitted the output shaft, drive mechanism includes:

2. The power tool of claim 1, wherein a ratio of a rotational speed of the connector to a rotational speed of the output shaft is greater than or equal to 2.

3. The power tool according to claim 2, wherein a ratio of a rotational speed of the connecting member to a rotational speed of the output shaft is 2 to 4.

4. The power tool of claim 1, wherein the reduction gear set includes a drivingly connected input gear and output member, the output member being connected to the output shaft, the input gear being connected to the connecting member.

5. The power tool of claim 4, wherein the reduction gear set is a first planetary gear train comprising the input gear, a number of first planet gears surrounding and engaging the input gear, a first ring gear engaged with the number of first planet gears, and the output carrying the number of first planet gears.

6. The power tool of claim 4, wherein the reduction gear set is a fixed-axis gear train, the output member is a gear, the fixed-axis gear train includes an input gear, a plurality of fixed gears surrounding and engaging the input gear, the output member engaging the plurality of fixed gears, and a carrier carrying the plurality of fixed gears, the fixed gears include a first gear portion and a second gear portion coaxially disposed, the first gear portion engaging the input gear, the second gear portion engaging the output member.

7. The power tool of claim 4, wherein the output member includes an annular gear portion and a connecting portion, the connecting portion has a rotation stopping hole, the output shaft and the rotation stopping hole are inserted to form a rotation stopping structure, and the annular gear portion is meshed with the input gear.

8. The power tool of claim 4, wherein the input gear is integrally connected with the connector.

9. The power tool of claim 1, wherein the impact mechanism has a drive shaft, and the end of the connector facing the impact mechanism has a first connecting hole, and the drive shaft is inserted into the first connecting hole.

10. The power tool according to claim 9, wherein an axially inner wall of the first connecting hole is held with the drive shaft by a ball.