Electric tool

Abstract

The invention discloses an electric tool. The electric tool comprises a shell; the motor is contained in the shell and comprises a stator assembly and a rotor assembly, the rotor assembly comprises a rotor shaft, and the rotor shaft drives a small gear arranged at the front end of the rotor shaft; a main shaft disposed in front of the rotor shaft and driven to rotate by the pinion, the front end of the main shaft having a first opening; the anvil block is arranged in front of the main shaft, a second opening used for containing the tool head is formed in the front end of the anvil block, the second opening comprises a limiting part used for limiting the insertion depth of the tool head, and the rear end of the anvil block is contained in the first opening and matched with the first opening so as to be driven by the main shaft to rotate; the axial distance between the limiting part and the foremost end of the first opening is smaller than or equal to 5 mm. By the adoption of the technical scheme, the electric tool small in size can be provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tools, in particular to an electric tool. BACKGROUND

[0002] Electric tools are more environmentally friendly than engine tools, and thus are widely used. Electric tools generally use motors to drive work. Impact tools are electric tools that can output rotary motion at a certain impact frequency. Common impact tools include impact wrenches, which are usually used to rotate bolts and nuts.

[0003] The working conditions of impact wrenches are gradually developing towards refinement. Users often need impact wrenches to be small and easy to control, so that they can work well in relatively small spaces.

[0004] This part provides background information related to the present application, which may not be prior art. SUMMARY

[0005] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide an electric tool with a smaller size.

[0006] To achieve the above object, the present application adopts the following technical solution:

[0007] An electric tool, comprising: a housing; a motor housed in the housing, the motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising a rotor shaft, the rotor shaft driving a pinion gear disposed at a front end of the rotor shaft; a main shaft disposed in front of the rotor shaft, the main shaft being driven to rotate by the pinion gear, a front end of the main shaft forming a first opening; and an anvil disposed in front of the main shaft, a front end of the anvil forming a second opening for accommodating a tool head, the second opening comprising a limiting portion limiting an insertion depth of the tool head, a rear end of the anvil being accommodated in the first opening and cooperating with the first opening to be driven to rotate by the main shaft; an axial distance between the limiting portion and a frontmost end of the first opening being less than or equal to 5 mm.

[0008] In some embodiments, when a double-head tool head is installed in the anvil, an axial distance between a rear end of the double-head tool head and the frontmost end of the first opening is less than or equal to 5 mm.

[0009] In some embodiments, when a single-head tool head is installed in the anvil, an axial distance between a rear end of the single-head tool head and the frontmost end of the first opening is less than or equal to 5 mm.

[0010] In some embodiments, the electric tool comprises a chuck bushing, the anvil comprises an anvil bushing, and the axial positions of the chuck bushing and the anvil bushing at least partially overlap.

[0011] In some embodiments, the electric power tool comprises a gear button and a battery pack, the gear button is used to control the working gear of the electric power tool, and the gear button is arranged on the side of the battery pack.

[0012] In some embodiments, the inner diameter of the first opening is greater than or equal to 6 mm.

[0013] In some embodiments, the outer diameter of the first opening is greater than or equal to 1.5 times the inner diameter of the opening.

[0014] In some embodiments, the distance between the last edge of the housing and the frontmost edge of the anvil is less than or equal to 95 mm.

[0015] In some embodiments, an electric power tool comprises: a housing; a motor accommodated in the housing, the motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising a rotor shaft, the rotor shaft driving a pinion gear arranged at the front end of the rotor shaft; a main shaft arranged in front of the rotor shaft and driven to rotate by the pinion gear, the front end of the main shaft being formed with a first opening; and an anvil arranged in front of the main shaft, the front end of the anvil being formed with a second opening for accommodating a tool head, the rear end of the anvil being accommodated in and cooperating with the first opening to be driven to rotate by the main shaft; the outer diameter of the first opening is greater than or equal to 15 mm, and the distance between the last edge of the housing and the frontmost edge of the anvil is less than or equal to 95 mm.

[0016] In some embodiments, the inner diameter of the first opening is greater than or equal to 6 mm.

[0017] In some embodiments, the electric power tool comprises a chuck bushing, the anvil comprises an anvil bushing, and the axial positions of the chuck bushing and the anvil bushing at least partially overlap.

[0018] In some embodiments, the electric power tool comprises a gear button and a battery pack, the gear button is used to control the working gear of the electric power tool, and the gear button is arranged on the side of the battery pack.

[0019] In some embodiments, the tool head is a single-head tool head.

[0020] In some embodiments, the tool head is a double-head tool head.

[0021] In some embodiments, the second opening comprises a limiting portion limiting the insertion depth of the tool head, and the axial distance between the limiting portion and the frontmost end of the first opening is less than or equal to 6 mm.

[0022] The present application has the advantage of providing an electric power tool with a smaller size. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a side view of an impact wrench of an embodiment;

[0024] Figure 2 is a cross-sectional view of the impact wrench in Figure 1

[0025] Figure 3 is a side view of the pinion gear and bearing of the impact wrench in Figure 1

[0026] Figure 4 is an exploded perspective view of the drive assembly and impact assembly of the impact wrench in Figure 1

[0027] Figure 5 is a cross-sectional view of the rotor shaft and pinion gear of the impact wrench of one embodiment formed as a single piece;

[0028] Figure 6 is a perspective view of the rotor shaft and pinion gear of the impact wrench in Figure 5

[0029] Figure 7 is a cross-sectional view of the rotor shaft and pinion gear of the impact wrench of one embodiment formed as separate pieces;

[0030] Figure 8 is a perspective view of the rotor shaft and pinion gear of the impact wrench in Figure 7

[0031] Figure 9 is a partial cross-sectional view of the impact wrench in Figure 1

[0032] Figure 10 is a close-up view of the front bearing and stator assembly of the impact wrench in Figure 9

[0033] Figure 11 is a close-up view of the rear cover and spindle of the impact wrench in Figure 9

[0034] Figure 12 is a cross-sectional view of the spindle and anvil of the impact wrench in Figure 1

[0035] Figure 13 is a cross-sectional view of the impact structure of the impact wrench in Figure 1 DETAILED DESCRIPTION

[0036] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above-described accompanying drawings.

[0037] ​​​​​​​​​​In this application, the terms "include", "comprise" or "have" or any other variations thereof are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or apparatuses that include a list of elements are not limited to those elements, but can include other elements not expressly listed or inherent to such processes, methods, articles, or apparatuses. Without further limitation, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0038] In this application, the term "and / or", is a description of an associated object, which means that there can be three kinds of relations. For example, A and / or B, can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this application generally indicates that the front and rear associated objects are in a "and / or" relationship.

[0039] In this application, the terms "connect", "combine", "couple", "mount" can be direct connection, combination, coupling or mounting, or indirect connection, combination, coupling or mounting. Among them, direct connection refers to the connection of two parts or components without the need for an intermediate part, and indirect connection refers to the connection of two parts or components with at least one intermediate part. In addition, "connection" and "coupling" are not limited to physical or mechanical connection or coupling, and can include electrical connection or coupling.

[0040] In this application, those of ordinary skill in the art will understand that relative terms used in connection with quantities or conditions (such as "about", "approximately", "substantially" and the like) include the values described and have the meaning indicated by the context. For example, the relative terms at least include the degree of error related to the measurement of a particular value, the tolerance caused by manufacturing, assembly, use, etc. related to a particular value. Such terms should also be considered to disclose the range defined by the absolute values of the two endpoints. The relative term can refer to a certain percentage (such as 1%, 5%, 10% or more) of the indicated value. The numerical value without the relative term should also be disclosed as a specific value with a tolerance. In addition, "substantially" when expressing the relative angular positional relationship (for example, substantially parallel, substantially perpendicular), can refer to a certain degree (such as 1 degree, 5 degrees, 10 degrees or more) added or subtracted from the indicated angle.

[0041] In this application, those of ordinary skill in the art will understand that the functions performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by a part can also be performed by one part, one component, or multiple parts in combination.

[0042] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and the like are described in the orientation and positional relationship shown in the drawings, and should not be understood as a limitation on the embodiments of the present application. In addition, it is also understood in the context that when referring to an element connected to another element "on" or "under", it can be directly connected to another element "on" or "under" or indirectly connected to another element "on" or "under" through an intermediate element. It should also be understood that the terms "upper", "lower", "left", "right", "front", "back" and the like not only represent the positive direction, but also can be understood as the side direction. For example, the lower side can include the directly below, left below, right below, front below and back below, etc.

[0043] As shown in Figures 1-2 An electric tool of an embodiment of the present application is shown, in which the impact tool is an impact wrench 100. It can be understood that the impact wrench 100 is a rotary tool which can be installed with different working accessories. In other alternative embodiments, the electric tool can also be, for example, a drill, a drywall screwdriver, an angle grinder, etc. In order to facilitate the description of the technical solutions, the terms such as Figure 1 are defined as shown: front side, back side, upper side and lower side. Among them, the front-back direction is the axial direction of the impact wrench 100, and the up-down direction is the radial direction of the impact wrench 100.

[0044] As shown in Figure 1 The impact wrench 100 of an embodiment of the present application shown includes a power supply. Among them, the power supply is used to provide power for the impact wrench 100. In the present embodiment, the power supply includes a direct current power supply 200, for example, the direct current power supply 200 is a battery pack, which cooperates with the corresponding power supply circuit to supply power to the corresponding components in the impact wrench 100. It should be understood by those skilled in the art that the power supply is not limited to the scene of using the battery pack, but also can be realized by the mains, alternating current power supply, cooperating with the corresponding rectifier, filter and voltage regulating circuit to realize the power supply to the corresponding components in the machine. In the present embodiment, the direct current power supply 200 is specifically set as a battery pack, and hereinafter the battery pack 200 will be used instead of the direct current power supply, but it cannot be regarded as a limitation on the present application.

[0045] As shown in Figures 1-3 The impact wrench 100 includes a housing 110, a motor 120, an output assembly 130, a transmission assembly 140 and an impact assembly 150. As can be seen from the following, the above-mentioned assemblies can share part of the structure, therefore, the present disclosure does not intend to limit the above-mentioned assemblies as completely independent parts.

[0046] The motor 120 includes a rotor assembly 121 and a stator assembly 122. The rotor assembly 121 includes a rotor core 1211 and a rotor shaft 1212, with the rotor shaft 1212 protruding from the end face of the rotor core 1211 in a front-rear direction. The rotor shaft 1212 rotates about a first axis 101. The stator assembly 122 includes a stator winding 1221 and a stator core 1222, with the stator winding 1221 wound around the stator core 1222. In this embodiment, the motor 120 is an inner rotor brushless motor. In other alternative embodiments, the motor 120 is an outer rotor brushless motor. For an inner rotor motor, the stator core 1222 is disposed outside the rotor assembly 121. For an outer rotor motor, the rotor assembly 121 is sleeved outside the stator core 1222. In this embodiment, the brushless motor is configured as a three-phase brushless motor. It is understood that the motor is not limited to a three-phase brushless motor, but can also be other types of DC motors, and the above does not affect the substantive content of this application.

[0047] In some embodiments, the width of the motor 120 is 52 mm. In some embodiments, the stack length of the rotor assembly 121 is 8.5 mm, and the maximum axial length of the rotor assembly 121 is 38.5 mm. In some embodiments, the stack length of the stator assembly 122 is 8 mm, and the maximum axial length of the stator assembly 122 is 20.8 mm.

[0048] The housing 110 includes a motor housing 111 for accommodating a motor 120 and an output housing 112 for accommodating at least a portion of the output assembly 130, the output housing 112 being connected to the front end of the motor housing 111. The housing 110 also forms or is connected to a user-operated grip portion 113. The grip portion 113 and the motor housing 111 form a T-shaped or L-shaped structure for easy gripping and operation by the user. One end of the grip portion 113 is connected to a battery pack 200. The battery pack 200 is detachably connected to the grip portion 113.

[0049] like Figure 1 As shown, the impact wrench 100 also includes a switch 160, which is a trigger switch. The trigger switch is provided on the grip 113 for the user to operate and control the impact wrench 100.

[0050] The output assembly 130 includes an output section 131 for connecting the tool head and outputting power to drive the tool head to rotate. The front end of the output section 131 is provided with a clamping assembly, which can clamp the corresponding tool head, such as a screwdriver bit, drill bit, or socket, when performing different functions.

[0051] The output section 131 is used to output power, and it rotates about the output axis 102. In this embodiment, the first axis 101 coincides with the output axis 102. In other alternative embodiments, the output axis 102 and the first axis 101 are set at a certain angle. In other alternative embodiments, the first axis 101 and the output axis 102 are parallel to each other but do not coincide.

[0052] like Figure 2 and Figure 4 As shown, the impact assembly 150 provides impact force to the output section 131. The impact assembly 150 includes a main shaft 151, an impact block 152 sleeved around the outer periphery of the main shaft 151, an anvil 153 disposed at the front end of the impact block 152, and an elastic element 154. The anvil 153 is connected to the output section 131. The output section 131 is formed or connected to the front end of the anvil 153. It is understood that the anvil 153 and the output section 131 can be integrally formed or separately formed independent parts.

[0053] The impact block 152 is driven to rotate by the rotor shaft 1212, the anvil 153 cooperates with the impact block 152 and is struck by it, and the main shaft 151 connects the impact block 152 and the rotor shaft 1212. In some embodiments, the rotor shaft 1212 drives the main shaft 151, and the main shaft 151 drives the impact block 152 to rotate.

[0054] The output section 131 extends out of the output housing 112. The impact block 152 is supported on the main shaft 151, rotates integrally with the main shaft 151, and can reciprocate relative to the main shaft 151 in the axial direction of the main shaft 151. In some embodiments, the axis of the main shaft 151 coincides with the axis of the rotor shaft 1212; therefore, the impact block 152 reciprocates and rotates relative to the main shaft 151 along the direction of the first axis 101. In some embodiments, the axis of the main shaft 151 may be parallel to but not coincident with the axis of the rotor shaft 1212, or the axis of the main shaft 151 and the axis of the rotor shaft 1212 may be set at a certain angle.

[0055] The elastic element 154 provides a force to the impact block 152 to bring it closer to the anvil 153. Optionally, the elastic element 154 can be a coil spring. During the operation of the impact wrench 100, the impact block 152 rotates integrally with the spindle 151 while reciprocating back and forth relative to the spindle 151 along the first axis 101 with a predetermined stroke.

[0056] When the impact wrench 100 is unloaded, the impact assembly 150 does not impact, and the impact assembly 150 functions as a transmission to transmit the rotation of the motor 120 to the output 131. When the impact wrench 100 is loaded, the rotation of the output 131 is blocked, and the output 131 can rotate at a reduced speed or can completely stop rotating due to different sizes of the load. When the output 131 completely stops rotating, the anvil 153 also stops rotating, and the anvil 153 is completely separated from the impact block 152. The main shaft 151 drives the impact block 152 to rotate at a certain speed, and the elastic element 154 rebounds in the axial direction. The relative rotation speed between the impact block 152 and the anvil 153 is the rotation speed of the impact block 152. When the impact block 152 rotates to contact the anvil 153, an impact force is applied to the anvil 153. Under the action of the impact force, the output 131 continues to rotate by a certain angle to overcome the load, and then the output 131 stops rotating again to repeat the above process. Since the impact frequency is large enough, a relatively continuous impact force is generated on the output 131, so that the working accessory continuously works.

[0057] The transmission assembly 140 is configured to transmit the torque output by the rotor shaft 1212 to the output 131. In this embodiment, the transmission assembly 140 is arranged between the motor 120 and the impact assembly 150, and is used to realize power transmission between the rotor shaft 1212 and the main shaft 151. In this embodiment, the transmission assembly 140 adopts planetary gear deceleration. Because the working principle of planetary gear deceleration and the deceleration generated by this transmission assembly are fully disclosed to those skilled in the art, detailed description is omitted here for the purpose of brevity of the specification.

[0058] In some embodiments, as shown in FIG. 1, the overall height H1 of the impact wrench 100 can be 199.5 mm. In some embodiments, as shown in FIG. 2, the center height H2 of the impact wrench 100 can be 31 mm. Figure 2 Figure 2

[0059] In some embodiments, the output power of the motor 120 is less than or equal to 630 W. Optionally, the output power of the motor 120 is 600 W. Optionally, the output power of the motor 120 is 580 W. Optionally, the output power of the motor 120 is 550 W. Optionally, the output power of the motor 120 is 400 W.

[0060] In some embodiments, the output torque of the impact wrench 100 is less than or equal to 150 Nm. Optionally, the output torque of the impact wrench 100 is 130 Nm. Optionally, the output torque of the impact wrench 100 is 110 Nm. Optionally, the output torque of the impact wrench 100 is 100 Nm. Optionally, the output torque of the impact wrench 100 is 80 Nm.

[0061] ​​In some embodiments, such as Figure 3 As shown, a pinion 300 is provided at the front end of the rotor shaft 1212. The rotor shaft 1212 drives the pinion 300, which in turn drives the output unit 131. Specifically, the rotation of the rotor shaft 1212 drives the pinion 300 to rotate. The rotor shaft 1212 and the pinion 300 rotate synchronously, which in turn drives the planetary gear meshing with it to rotate. The planetary gear drives the output unit 131. A bearing 400 is provided behind the pinion 300 and is sleeved on the rotor shaft 1212 to support it. The rotor shaft 1212 may have a protrusion for the bearing 400 to be sleeved on. Alternatively, the rotor shaft 1212 may not have a protrusion, and the bearing 400 may be directly sleeved on it. Optionally, the inner diameter D1 of the bearing 400 is smaller than the diameter D2 of the pinion 300. Optionally, the inner diameter D1 of the bearing 400 is less than or equal to 7 mm. Optionally, the inner diameter D1 of bearing 400 is 6 mm. Optionally, the inner diameter D1 of bearing 400 is 5.5 mm. Optionally, the inner diameter D1 of bearing 400 is 4.8 mm. Optionally, the diameter D2 of pinion 300 is greater than or equal to 7 mm. Optionally, the diameter D2 of pinion 300 is 7.5 mm. Optionally, the diameter D2 of pinion 300 is 8 mm. Optionally, the diameter D2 of pinion 300 is 8.3 mm. Optionally, the diameter D2 of pinion 300 is 9 mm.

[0062] In some embodiments, since the bearing 400 is sleeved on the front end of the rotor shaft 1212, the outer diameter D3 of the bearing 400 is larger than the diameter D4 of the rotor shaft 1212. Optionally, the outer diameter D3 of the bearing 400 is greater than or equal to 8 mm and less than or equal to 16 mm. Optionally, the outer diameter D3 of the bearing 400 is 15 mm. Optionally, the outer diameter D3 of the bearing 400 is 14.5 mm. Optionally, the outer diameter D3 of the bearing 400 is 14 mm. Optionally, the outer diameter D3 of the bearing 400 is 13.8 mm. Optionally, the diameter D4 of the rotor shaft 1212 is greater than or equal to 7 mm. Optionally, the diameter D4 of the rotor shaft 1212 is 7.5 mm. Optionally, the diameter D4 of the rotor shaft 1212 is 8 mm. Optionally, the diameter D4 of the rotor shaft 1212 is 8.3 mm.

[0063] Optionally, the distance S1 between the bearing 400 and the pinion 300 is less than or equal to 12 mm. Specifically, the distance S1 between the bearing 400 and the pinion 300 is the distance between the center point of the bearing 400 and the center point of the pinion 300.

[0064] In some embodiments, the rotor shaft 1212 and the pinion 300 are integrally formed. Specifically, the pinion 300 is formed directly at the front end of the rotor shaft 1212. Figure 5As shown, the rotor shaft 1212 further comprises a protrusion 1213. The pinion 300 is located at the front end of the rotor shaft 1212, specifically at the front end of the protrusion 1213, and the bearing 400 is located at the rear of the pinion 300, specifically at the rear end of the protrusion 1213. Among them, a protrusion is arranged on the rotor shaft 1212 for the bearing 400 to be sleeved, and the width of the protrusion where the bearing 400 is sleeved is smaller than the protrusion of the protrusion 1212, so that the bearing 400 is limited to the rear end of the protrusion 1213. Among them, the bearing 400 is a front bearing, and the following will be described in detail with the front bearing 400 instead of the bearing 400. The distance S2 between the front bearing 400 and the protrusion 1213, and the distance S3 between the protrusion 1213 and the pinion 300 are both less than 8.5mm. Among them, the distance S2 between the front bearing 400 and the protrusion 1213 is specifically the distance between the center point of the front bearing 400 and the center point of the protrusion 1213. The distance S3 between the protrusion 1213 and the pinion 300 is specifically the distance between the center point of the protrusion 1213 and the center point of the pinion 300.

[0065] Optionally, as shown in Figure 5 The inner diameter D1 of the front bearing 400 is smaller than the outer diameter of the protrusion 1213. Therefore, after the front bearing 400 is sleeved on the rotor shaft 1212, it can be limited by the protrusion 1213 and cannot move forward again. The diameter D2 of the pinion 300 is greater than the diameter of the rotor shaft 1212, and the diameter D2 of the pinion 300 is smaller than the outer diameter of the protrusion 1213. Because the diameter D2 of the pinion 300 is smaller than the outer diameter of the protrusion 1213, and the rotor shaft 1212 and the pinion 300 are integrally formed. Therefore, the front bearing 400 and the rotor assembly 121 and other related structures cannot be assembled to the rotor shaft 1212 from front to back like the prior art. The front bearing 400 and the rotor assembly 121 and other related structures are assembled to the rotor shaft 1212 as shown in Figure 6 Figure 6 The structure shown in is assembled to the rotor shaft 1212 from back to front. The assembly method comprises: first, sleeving the front bearing 400 on the rotor shaft 1212 from the rear end of the rotor shaft 1212, and moving the front bearing 400 forward until the front bearing 400 is limited by the protrusion 1213 and cannot move forward again. Then, the rotor assembly 121 and the fan are sleeved on the rotor shaft 1212 from back to front in sequence. Optionally, the rotor assembly 121 can be pre-installed as a whole and sleeved on the rotor shaft 1212. Optionally, the rotor assembly 121 can also sequentially sleeve the front end plate, rotor core 1211, magnetic shoe, gasket and rubber pad included therein on the rotor shaft 1212 from back to front, and combine to form the rotor assembly 121 as a whole on the rotor shaft 1212. Finally, the rear bearing 410 is sleeved on the rotor shaft 1212 to support the rotor shaft 1212. And the front bearing 400 and the rear bearing 410 jointly limit and fix the rotor assembly 121 in the axial direction on the rotor shaft 1212.​

[0066] In some embodiments, the outer diameter of the front bearing 400 is less than or equal to 1.5 times the outer diameter of the rear bearing 410. Optionally, the outer diameter of the front bearing 400 is equal to the outer diameter of the rear bearing 410, so that the front bearing 400 occupies less space in the radial direction of the impact wrench 100, so as to provide more space in the radial direction of the impact wrench 100, facilitating the partial overlap of the front bearing 400, the stator assembly 122, the rear cover 143, the main shaft 141 and other structures in the axial direction.

[0067] In some embodiments, the rotor shaft 1212 and the pinion gear 300 are separately arranged. As shown in Figure 7 and Figure 8 The rotor shaft 1212 includes an axial recess 1214, and the pinion gear 300 includes an axial extension 310, which can cooperate with the axial recess 1214 to fixedly mount the pinion gear 300 on the rotor shaft 1212. Specifically, the axial extension 310 is inserted into the axial recess 1214. The front bearing 400 is arranged on the axial extension 310. The axial extension 310 includes a first extension 311 and a second extension 312, the first extension 311 being the portion inserted into the axial recess 1214, and the second extension 312 being the portion on which the front bearing 400 is arranged, the diameter of the second extension 312 matching the inner diameter of the front bearing 400. Optionally, the diameters of the first extension 311 and the second extension 312 can be different. Specifically, the diameter of the first extension 311 is smaller than that of the second extension 312, so that the front bearing 400 can be sleeved on the second extension 312 after passing through the first extension 311. Optionally, the diameters of the first extension 311 and the second extension 312 can also be the same, and in this case, the diameters of the first extension 311 and the second extension 312 both match the inner diameter of the front bearing 400. As shown in Figure 7 and Figure 8 In this case, the rotor shaft 1212 also includes a protrusion 1213 to limit the front bearing 400.

[0068] Optionally, the cooperation between the axial extension 310 and the axial recess 1214 can be interference mounting, so as to avoid the existence of a gap between the axial extension 310 and the axial recess 1214, so that the axial extension 310 can be better fixedly mounted in the axial recess 1214, so that the axial extension 310 and the axial recess 1214 do not slide relative to each other during the operation of the impact wrench 100.

[0069] By setting the rotor shaft 1212 and the pinion 300 as one-piece, i.e. setting the rotor shaft 1212 as a gear shaft, the rotor shaft 1212 can transmit torque. Meanwhile, when the rotor shaft 1212 is one-piece or the pinion 300 is inserted into the rotor shaft 1212, since the front bearing 400 is sleeved on the rotor shaft 1212 from back to front, the part of the rotor shaft 1212 matched with the front bearing 400 has a smaller diameter, i.e. the inner diameter of the front bearing 400 is smaller. Since the size ratio of the front bearing 400 is certain, the axial length and the radial length of the front bearing 400 are both smaller, so that the overall length and the radial size of the impact wrench 100 are both shortened.

[0070] In some embodiments, the front bearing 400 and the stator assembly 122 at least partially overlap in the axial position. As shown in Figure 10 , the front bearing 400 and the stator assembly 122 overlap in the axial position, so that the length of the impact wrench 100 in the axial direction is further shortened.

[0071] In some embodiments, as shown in Figure 2 and Figure 4 , the transmission assembly 140 includes a main shaft 141, which is arranged in the extension direction of the rotor shaft 1212, specifically in the extension direction of the front end of the rotor shaft 1212. The main shaft 141 included in the transmission assembly 140 and the main shaft 151 included in the impact assembly 150 are the same structure, and for the sake of description, the main shaft 141 is used to indicate the structure hereinafter.

[0072] The main shaft 141 includes a plurality of planetary shafts 1411, which can be parallel to the extension direction of the rotor shaft 1212. The transmission assembly 140 includes a plurality of planetary gears 142, and the number of the plurality of planetary shafts 1411 is the same as the number of the plurality of planetary gears 142. The plurality of planetary gears 142 are arranged around the plurality of planetary shafts 1411, specifically, the plurality of planetary gears 142 are sleeved on the plurality of planetary shafts 1411. Figure 9 As shown in , the main shaft 141 has a recess on the rear side matched with the pinion 300, and the pinion 300 extends into the recess of the main shaft 141 and drives the plurality of planetary gears 142. Specifically, the pinion 300 is engaged with the plurality of planetary gears 142, and the pinion 300 is located in the middle of the plurality of planetary gears 142. The rotation of the pinion 300 can drive the rotation of the plurality of planetary gears 142.

[0073] The transmission assembly 140 further comprises a rear cover 143, which surrounds at least a part of the main shaft 141 from rear to front. The rear cover 143 is a gear box rear cover 143, and the gear box is composed of the pinion 300 and the plurality of planetary gears 142. In some embodiments, the rear cover 143 is formed with an inner ring gear 1431, i.e. the inner ring gear 1431 is directly formed on the inside of the rear cover 143, without the need for a separate inner ring gear as in the prior art, so that the overall length and radial dimension of the impact wrench 100 are shortened. The inner ring gear 1431 is engaged with the plurality of planetary gears 142, and the plurality of planetary gears 142 rotate in the inner ring gear 1431.

[0074] In some embodiments, the impact wrench 100 does not have a bearing for the main shaft 141, and the main shaft 141 is directly in contact with the rear cover 143, and the main shaft 141 is limited by the rear cover 143. Therefore, when the plurality of planetary gears 142 rotate in the inner ring gear 1431, the rear cover 143 and the main shaft 141 are in sliding contact with each other. Specifically, the main shaft 141 extends into the rear cover 143, and when the plurality of planetary gears 142 rotate, the main shaft 141 rotates relative to the rear cover 143, i.e. the main shaft 141 slides and rotates in the rear cover 143. In this way, the impact wrench 100 is further shortened in the axial direction without a bearing for the main shaft 141. The main shaft 141 will constantly rub against the rear cover 143 during the rotation of the plurality of planetary gears 142 in the inner ring gear 1431, and therefore the material hardness of the contact area between the rear cover 143 and the main shaft 141 is greater than or equal to 20HRC, which improves the wear resistance of the rear cover 143. Optionally, the material hardness of the contact area between the rear cover 143 and the main shaft 141 is 25HRC. Optionally, the material hardness of the contact area between the rear cover 143 and the main shaft 141 is 30HRC. Optionally, the material hardness of the contact area between the rear cover 143 and the main shaft 141 is 37HRC. Optionally, the material hardness of the contact area between the rear cover 143 and the main shaft 141 is 42HRC. Optionally, the material hardness of the contact area between the rear cover 143 and the main shaft 141 is 50HRC.

[0075] In some embodiments, the material of the rear cover 143 is powder metallurgy. In some embodiments, the contact area between the rear cover 143 and the main shaft 141 is hardened by carburizing treatment, so that the surface layer of the contact area between the rear cover 143 and the main shaft 141 has high hardness and wear resistance, while the central part of the contact area still maintains the toughness and plasticity of low carbon steel. In addition, the contact area between the rear cover 143 and the main shaft 141 can also use any other method that can achieve high surface hardness and high toughness of the central part, which is not limited in the present application.

[0076] In some embodiments, as shown in FIG. 1, the impact wrench 100 further comprises a handle 110, a power supply assembly 120, a transmission assembly 140, and a tool head 130. Figure 11As shown, since the main shaft 141 is without bearing, and the rear cover 143 is formed with the inner ring gear 1431, the rear cover 143 and the main shaft 141 have a portion which overlaps in the axial direction. The portion where the rear cover 143 and the main shaft 141 overlap in the axial direction includes the contact area X of the two. As can be seen from the figure, the contact area of the two includes both axial contact area and longitudinal contact area. In some embodiments, the axial overlap length of the contact area of the rear cover 143 and the main shaft 141 is greater than or equal to 1.5 mm, i.e. the sliding fit distance of the rear cover 143 and the main shaft 141 is greater than or equal to 1.5 mm. In some embodiments, as shown in FIG. 1, the rear cover 143 and the main shaft 141 are in sliding fit. Figure 11 As shown, the main shaft 141 also at least partially overlaps with the axial position of the stator assembly 122. In the prior art, the rear cover and the main shaft, the stator assembly and the main shaft do not overlap in the axial direction, so that the overall length of the impact wrench 100 is relatively long. In the present application, by setting the contact area of the rear cover 143 and the main shaft 141 to partially overlap in the axial direction, and the main shaft 141 and the stator assembly 122 to partially overlap in the axial direction, the overall length of the impact wrench 100 is shortened.

[0077] In some embodiments, the impact wrench 100 includes a support portion, which is provided at the rear of the main shaft 141 for supporting the main shaft 141. In the present embodiment, the support portion is the rear cover 143, which supports the main shaft 141. In other embodiments, in the case of an electric tool including a main shaft bearing, the support portion is the main shaft bearing, which supports the main shaft 141.

[0078] Optionally, the support portion, the stator assembly 122 and the front bearing 400 at least partially overlap in the axial position. As shown in FIG. 1, Figure 10 As shown, the rear cover 143, the stator assembly 122 and the front bearing 400 at least partially overlap in the axial position. Optionally, the main shaft 141 and the front bearing 400 partially overlap in the axial position. Optionally, as shown in FIG. 1, Figure 9 As shown, the front bearing 400, the stator assembly 122, the rear cover 143 and the main shaft 141 at least partially overlap in the axial position. By setting the front bearing 400, the stator assembly 122, the rear cover 143 and the main shaft 141 to partially overlap in the axial position, the impact wrench 100 has a portion in the axial direction which can be simultaneously occupied by the front bearing 400, the stator assembly 122, the rear cover 143 and the main shaft 141, so that the axial length of the impact wrench 100 is relatively short.

[0079] In some embodiments, the anvil 153 and the output portion 131 are integrally formed, i.e. the output portion 131 is the anvil 153, and the present application will be described with the anvil 153 representing the output portion 131. The anvil 153 is used for mounting a tool head and outputting power outwardly.

[0080] In some embodiments, the front end of the main shaft 141 is formed with a first opening 1412 for accommodating the rear end of the anvil 153, and the first opening 1412 cooperates with the rear end of the anvil 153 to drive the anvil 153 to rotate. As shown in Figure 12 the rear end of the anvil 153 is formed with an anvil protrusion 1531 which cooperates with the first opening 1412, specifically, the anvil protrusion 1531 is inserted into the first opening 1412. Optionally, the anvil protrusion 1531 and the first opening 1412 can be interference fitted, so that the anvil protrusion 1531 can be better fixedly installed in the first opening 1412, so that during the working process of the impact wrench 100, the first opening 1412 can always drive the anvil protrusion 1531 to rotate, that is, the main shaft 141 can always drive the anvil 153 to rotate, and the anvil 153 will not slide relative to the main shaft 141.

[0081] In some embodiments, the inner diameter D5 of the first opening 1412 is greater than or equal to 6 mm. Optionally, the inner diameter D5 of the first opening 1412 is 6.5 mm. Optionally, the inner diameter D5 of the first opening 1412 is 7 mm. Optionally, the inner diameter D5 of the first opening 1412 is 7.3 mm. Thus, the first opening 1412 can more stably and fixedly install the anvil protrusion 1531. In some embodiments, the outer diameter D6 of the first opening 1412 is greater than or equal to 1.5 times the opening inner diameter D5. For example, when the inner diameter D5 of the first opening 1412 is 6 mm, the outer diameter D6 of the first opening 1412 is greater than or equal to 9 mm. For example, when the inner diameter D5 of the first opening 1412 is 7 mm, the outer diameter D6 of the first opening 1412 is greater than or equal to 10.5 mm. For example, when the inner diameter D5 of the first opening 1412 is 9 mm, the outer diameter D6 of the first opening 1412 is greater than or equal to 13.5 mm.

[0082] By providing the first opening 1412 on the main shaft 141, part of the anvil 153 can be inserted into the main shaft 141. That is, in the axial direction of the impact wrench 100, the main shaft 141 and the anvil 153 partially overlap, so that when the length of the anvil 153 is constant, the overall length of the impact wrench 100 is shortened.

[0083] In some embodiments, the front end of the anvil 153 is formed with a second opening 1532 for accommodating a tool head, the second opening 1532 is used to install a tool head, and the second opening 1532 includes a limiting portion 1533 for limiting the insertion depth of the tool head. Optionally, the second opening 1532 is used to install a double-head tool head. Optionally, the second opening 1532 is used to install a single-head tool head.

[0084] In some embodiments, as shown in Figure 12As shown, the axial distance S4 between the limit portion 1533 and the most front end of the first opening 1412 is less than or equal to 5 mm. Optionally, the axial distance S4 between the limit portion 1533 and the most front end of the first opening 1412 is 4.5 mm. Optionally, the axial distance S4 between the limit portion 1533 and the most front end of the first opening 1412 is 4.2 mm. Optionally, the axial distance S4 between the limit portion 1533 and the most front end of the first opening 1412 is 3.5 mm.

[0085] In some embodiments, the axial distance between the rear end of the double-head tool head and the most front end of the first opening 1412 is less than or equal to 5 mm when the double-head tool head is installed in the anvil 153. Here, the rear end of the double-head tool head refers to the last end of the double-head tool head inserted into the second opening 1532, and the axial distance between the rear end of the double-head tool head and the most front end of the first opening 1412 is the shortest distance between the double-head tool head and the first opening 1412.

[0086] In some embodiments, the axial distance between the rear end of the single-head tool head and the most front end of the first opening 1412 is less than or equal to 5 mm when the single-head tool head is installed in the anvil 153. Here, the rear end of the single-head tool head refers to the last end of the single-head tool head inserted into the second opening 1532, and the axial distance between the rear end of the single-head tool head and the most front end of the first opening 1412 is the shortest distance between the double-head tool head and the first opening 1412.

[0087] In some embodiments, the anvil 153 comprises an anvil bushing 1534, and the impact wrench 100 comprises a chuck bushing 103. As shown in FIG. 1 1, Figure 12 As shown, the anvil bushing 1534 and the chuck bushing 103 at least partially overlap in the axial direction, thereby shortening the length occupied by the anvil bushing 1534 and the chuck bushing 103 in the axial direction without affecting the clamping of the tool head by the anvil 153, and shortening the overall length of the impact wrench 100.

[0088] In some embodiments, as shown in FIG. 1 1, Figure 2 As shown, the distance S5 between the last edge of the housing 1 10 and the most front edge of the anvil 153 is less than or equal to 95 mm, and the overall length of the impact wrench 100 is relatively small. Optionally, the distance S5 between the last edge of the housing 1 10 and the most front edge of the anvil 153 is 92 mm. Optionally, the distance S5 between the last edge of the housing 1 10 and the most front edge of the anvil 153 is 90 mm. Optionally, the distance S5 between the last edge of the housing 1 10 and the most front edge of the anvil 153 is 89.5 mm. Optionally, the distance S5 between the last edge of the housing 1 10 and the most front edge of the anvil 153 is 84 mm.

[0089] In some embodiments, as shown in FIG. 1 1, Figure 13As shown, the ratio of the axial movement distance L1 of the impact block 152 to the diameter D7 of the impact block 152 is less than or equal to 0.3. Optionally, the ratio of the axial movement distance L1 of the impact block 152 to the diameter D7 of the impact block 152 is 0.25. The ratio of the axial movement distance L1 of the impact block 152 to the diameter D7 of the impact block 152 is 0.2. In some embodiments, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the diameter D7 of the impact block 152 is less than or equal to 2.5. Optionally, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the diameter D7 of the impact block 152 is 2.3. Optionally, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the diameter D7 of the impact block 152 is 2.0. Optionally, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the diameter D7 of the impact block 152 is 1.8. In some embodiments, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the front-to-back length L2 of the impact block 152 is less than or equal to 4.7. Optionally, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the front-to-back length L2 of the impact block 152 is 4.5. Optionally, the ratio of the distance S5 between the last edge of the housing 110 and the foremost edge of the anvil 153 to the front-to-back length L2 of the impact block 152 is 4.1.

[0090] By reducing the axial movement distance L1 of the impact block 152 and increasing the diameter D7 of the impact block 152 under the condition that the axial movement distance L1 of the impact block 152 can meet the condition of full tripping of the impact block 152, the front-to-back length L2 of the impact block 152 is reduced. Thus, the output capacity of the impact wrench 100 is improved and the work efficiency of the user is improved under the condition that the axial length of the impact wrench 100 is small.

[0091] In some embodiments, the impact wrench 100 comprises a gear button 104 for controlling the working gear of the impact wrench 100. Since the overall length of the impact wrench 100 is shortened by the above-mentioned various methods, in order to avoid the battery pack 200 from contacting or colliding with the working surface during the working of the impact wrench 100, as shown in Figure 1 and Figure 2 The battery pack 200 is moved backward relative to the holding portion 113. At the same time, the gear button 104 is arranged on the side of the battery pack 200 away from the front, avoiding the problem of occupying the axial length of the impact wrench 100 if arranged in front of the battery pack 200. In some embodiments, if the impact wrench 100 is equipped with a 2-inch chuck, when the chuck is abutted against the surface of the workpiece, the distance between the foremost end of the battery pack 200 and the surface of the workpiece is 29 mm.

[0092] In some embodiments, the distance S6 between the forward most end of the battery pack 200 and the forward most edge of the anvil 153 is 3 mm, specifically, the battery pack 200 protrudes 3 mm relative to the forward most edge of the anvil 153. In some embodiments, the distance S7 between the battery pack 200 and the splayed foot forward end of the impact wrench 100 is 30 mm. In some embodiments, the distance S8 between the center of gravity of the battery pack 200 and the extension line of the handle 113 of the impact wrench 100 is 37 mm.

[0093] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. A power tool, comprising: a housing; a motor housed in the housing, the motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising a rotor shaft, the rotor shaft driving a pinion gear disposed at a front end of the rotor shaft; a spindle disposed in front of the rotor shaft, the spindle being driven to rotate by the pinion gear, a front end of the spindle being formed with a first opening; and an anvil disposed in front of the spindle, a front end of the anvil being formed with a second opening for accommodating a tool bit, the second opening comprising a limiting portion limiting an insertion depth of the tool bit, a rear end of the anvil being accommodated in and cooperating with the first opening to be driven to rotate by the spindle; characterized in that an axial distance between the limiting portion and a frontmost end of the first opening is less than or equal to 5 mm. When a double-head tool bit is installed in the anvil, an axial distance between a rear end of the double-head tool bit and the frontmost end of the first opening is less than or equal to 5 mm.

2. The power tool of claim 1, wherein, When a single-head tool bit is installed in the anvil, an axial distance between a rear end of the single-head tool bit and the frontmost end of the first opening is less than or equal to 5 mm.

3. The power tool of claim 1, wherein, The power tool comprises a chuck bushing, the anvil comprises an anvil bushing, and axial positions of the chuck bushing and the anvil bushing at least partially overlap.

4. The power tool of claim 1, wherein, The power tool comprises a gear button and a battery pack, the gear button being used to control a working gear of the power tool, and the gear button being disposed at a side of the battery pack away from a foot thereof.

5. The power tool of claim 1, wherein, An inner diameter of the first opening is greater than or equal to 6 mm.

6. The power tool of claim 1, wherein, An outer diameter of the first opening is greater than or equal to 1.5 times the inner diameter of the opening.

7. The power tool of claim 1, wherein, A distance between a last edge of the housing and a frontmost edge of the anvil is less than or equal to 95 mm.

8. The power tool of claim 1, wherein, 9. A power tool, comprising: a housing; a motor housed in the housing, the motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising a rotor shaft, the rotor shaft driving a pinion gear disposed at a front end of the rotor shaft; a spindle disposed in front of the rotor shaft, the spindle being driven to rotate by the pinion gear, a front end of the spindle being formed with a first opening; and an anvil disposed in front of the spindle, a front end of the anvil being formed with a second opening for accommodating a tool bit, a rear end of the anvil being accommodated in and cooperating with the first opening to be driven to rotate by the spindle; characterized in that an outer diameter of the first opening is greater than or equal to 1.5 times an inner diameter of the opening, and a distance between a last edge of the housing and a frontmost edge of the anvil is less than or equal to 95 mm. An inner diameter of the first opening is greater than or equal to 6 mm. The power tool comprises a chuck bushing, the anvil comprises an anvil bushing, and axial positions of the chuck bushing and the anvil bushing at least partially overlap.

10. The power tool of claim 9, wherein, The power tool comprises a gear button and a battery pack, the gear button being used to control a working gear of the power tool, and the gear button being disposed at a side of the battery pack away from a foot thereof.

11. The power tool of claim 9, wherein the control circuit is configured to: The tool bit is a single-head tool bit.

12. The power tool of claim 9, wherein, The tool bit is a double-head tool bit.

13. The power tool of claim 9, wherein the control circuit is configured to: The second opening comprises a limiting portion limiting an insertion depth of the tool bit, and an axial distance between the limiting portion and a frontmost end of the first opening is less than or equal to 6 mm.

14. The power tool of claim 9, wherein the control circuit is configured to: ​ 15. The power tool of claim 9, wherein the control circuit is configured to: ​

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