CN215148601U

CN215148601U - Impact screwdriver

Info

Publication number: CN215148601U
Application number: CN202121412620.8U
Authority: CN
Inventors: 刘少波; 王小勇
Original assignee: Nanjing Chervon Industry Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd
Priority date: 2021-06-24
Filing date: 2021-06-24
Publication date: 2021-12-14
Anticipated expiration: 2031-06-24

Abstract

The utility model discloses an impact screwdriver belongs to electric tool technical field. The utility model provides an impact screwdriver includes motor and gear box, the motor shaft of motor extends the setting along first direction a, the front end cover of motor shaft is equipped with the fore bearing, the gear box includes the back lid, the back is covered along the protruding salient structure that is equipped with of first direction a, the protrusion is structural to run through along first direction a and is provided with first through-hole, the motor shaft passes first through-hole setting, the at least part of fore bearing is arranged in first through-hole, the internal face butt of the at least part outer wall of fore bearing and first through-hole, the salient structure is at least in the stator of part embedding motor. This strike screwdriver covers the first through-hole of the protruding structure of going up behind the gear box through arranging the front bearing with the motor in to the front bearing of motor is supported to the lid behind the gear box, and at least part embedding motor stator, thereby has shortened the whole length of striking screwdriver, has improved holdability and user and has used experience.

Description

Impact screwdriver

Technical Field

The utility model relates to an electric tool technical field especially relates to an impact screwdriver.

Background

The impact screwdriver is a household common tool with an additional impact function, can be used for screwing a screw and punching, has the advantages of rapidness, convenience, cheapness, practicability, wide applicable crowd and the like, and is widely applied to family life.

The volume size of the impact screwdriver is an important factor in determining the user experience. The existing impact screwdriver has the problem of long overall length, and users experience poor experience when using the existing impact screwdriver, so that how to provide a small impact screwdriver with short overall length is a technical problem which needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an impact screwdriver, the complete machine length that should impact screwdriver is shorter, and user's use is experienced higher.

To achieve the purpose, the utility model adopts the following technical proposal:

an impact screwdriver, comprising:

the motor shaft of the motor extends along a first direction a, and a front bearing is sleeved at the front end of the motor shaft;

the gear box comprises a rear cover, a protruding structure is convexly arranged on the rear cover along the first direction a, a first through hole penetrates through the protruding structure along the first direction a, the motor shaft penetrates through the first through hole, at least part of the front bearing is arranged in the first through hole, at least part of the outer wall surface of the front bearing is abutted to the inner wall surface of the first through hole, and at least part of the protruding structure is embedded into a stator of the motor.

Preferably, the gear box comprises a main shaft, the main shaft is arranged along the first direction a, an assembly hole is arranged on the rear end, close to the rear cover, of the main shaft along the first direction a, and the end of the motor shaft extends into the assembly hole.

Preferably, the protruding structure is protruded toward the direction close to the motor, the front end structure of the front bearing is arranged in the assembly hole, and the front end outer wall surface of the front bearing is abutted against the inner wall surface of the assembly hole;

the rear end of the front bearing is arranged in the first through hole, and the outer wall surface of the rear end of the front bearing is abutted to the inner wall surface of the first through hole.

Preferably, the protruding structure protrudes in a direction away from the motor, the protruding structure is inserted into the assembly hole, and the front bearing is disposed in the first through hole.

Preferably, the gearbox further comprises a main shaft lower bearing;

and a bearing mounting groove is formed in the outer wall surface of the main shaft along the circumferential direction, and the lower bearing of the main shaft is arranged in the bearing mounting groove.

Preferably, projections of the main shaft lower bearing and the front bearing on a plane parallel to the first direction a at least partially overlap.

Preferably, the spindle lower bearing and the front bearing are embedded in a stator of the motor.

Preferably, the gearbox further comprises a planet wheel, the main shaft comprises a main body part and a ring convex part which are connected in a stepped columnar manner, a pin shaft hole is formed in the main body part, and a pin shaft of the planet wheel penetrates through the pin shaft hole.

Preferably, the annular convex part is provided with an avoiding groove for avoiding the pin shaft, and the avoiding groove is communicated with part of the pin shaft hole.

Preferably, the motor shaft is an integrated shaft formed with a driving gear.

The utility model has the advantages that:

the utility model provides an impact screwdriver, this impact screwdriver includes motor and gear box, the motor shaft of motor extends the setting along first direction a, the front end cover of motor shaft is equipped with the fore bearing, the gear box includes the back lid, the back is covered along the protruding salient structure that is equipped with of first direction a, the protrusion is structural to run through along first direction a and is provided with first through-hole, the motor shaft passes first through-hole setting, in first through-hole was arranged in to the at least part of fore bearing, the internal face butt of the at least part outer wall of fore bearing and first through-hole, the salient structure is at least in the stator of part embedding motor. This strike screwdriver covers the first through-hole of the protruding structure of going up behind the gear box through arranging the front bearing with the motor in to the front bearing of motor is supported to the lid behind the gear box, and at least part embedding motor stator, thereby has shortened the whole length of striking screwdriver, has improved holdability and user and has used experience.

Drawings

Fig. 1 is a schematic structural diagram of an impact screwdriver provided by the present invention;

FIG. 2 is a schematic view of the motor and gear box of the impact screwdriver provided by the present invention;

FIG. 3 is a cross-sectional view of a motor and gear box of an impact screwdriver according to an embodiment of the present invention;

FIG. 4 is an exploded view of the motor and gear box of a impact screwdriver according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a rear cover of an impact screwdriver according to an embodiment of the present invention at a certain viewing angle;

fig. 6 is a schematic structural diagram of a rear cover of an impact screwdriver according to another view angle in accordance with an embodiment of the present invention;

fig. 7 is a sectional view of a motor and a gear box of an impact screwdriver according to a second embodiment of the present invention;

fig. 8 is a schematic structural diagram of a rear cover of an impact screwdriver according to a second embodiment of the present invention at a certain viewing angle;

fig. 9 is a schematic structural diagram of a rear cover of an impact screwdriver according to a second embodiment of the present invention from another viewing angle;

fig. 10 is a schematic structural view of a spindle of an impact screwdriver according to a second embodiment of the present invention at a certain viewing angle;

fig. 11 is a schematic structural view of the main shaft of the impact screwdriver according to the second embodiment of the present invention at another viewing angle;

fig. 12 is a sectional view of a motor and a gear box of an impact screwdriver according to a third embodiment of the present invention;

fig. 13 is an exploded view of the motor and gear box of the impact screwdriver according to the third embodiment of the present invention;

fig. 14 is a schematic structural diagram of a rear cover of an impact screwdriver according to a third embodiment of the present invention at a certain viewing angle;

fig. 15 is a schematic structural diagram of a rear cover of an impact screwdriver according to a third embodiment of the present invention from another viewing angle.

In the figure:

100. an operation section; 200. a hand-held portion; 300. a battery section;

110. a motor; 111. a front bearing; 112. a motor shaft; 113. a drive gear;

120. a gear case; 121. a rear cover; 122. a protruding structure; 123. a first through hole; 124. a main shaft; 1241. a main body portion; 1242. a ring protrusion; 125. an assembly hole; 126. a main shaft lower bearing; 127. a bearing mounting cavity; 128. a pin shaft hole; 129. avoiding the groove.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

The embodiment provides an impact screwdriver which can assist in completing the work of punching, screwing screws and the like. As shown in fig. 1, the impact screwdriver comprises a working part 100, a handheld part 200 and a battery part 300, wherein the working part 100 is a main execution component of the impact screwdriver, a working head can be detachably connected to the main execution component, and the working head moves to complete various operations; the hand-held portion 200 is connected to the lower part of the working portion 100, and the two are in a substantially vertical state, and the hand-held portion 200 is held by a user; the battery part 300 is connected below the working part 100 and is used to power the movement of the working head.

As shown in fig. 2 to 4, the working unit 100 includes a housing, a motor 110, and a gear box 120, wherein an accommodating space is formed in the housing, and the motor 110 and the gear box 120 are both located in the housing. The motor 110 includes a motor shaft 112, and the motor shaft 112 extends in the first direction a in the accommodating space. The front end of the motor shaft 112 is sleeved with the front bearing 111, and the motor shaft 112 has two ends, wherein the end close to the gear box 120 is called a front end, and the end far away from the gear box 120 is called a rear end.

The gear box 120 and the motor 110 are arranged side by side along a first direction a, the gear box 120 includes a rear cover 121, a protruding structure 122 is convexly arranged on the rear cover 121 along the first direction a, and a first through hole 123 is penetratingly arranged on the protruding structure 122 along the first direction a. The front end of the motor shaft 112 is disposed through the first through hole 123 and is disposed inside the gear case 120. At least a part of the front bearing 111 is disposed in the first through hole 123, and at least a part of an outer wall surface of the front bearing 111 abuts against an inner wall surface of the first through hole 123.

In the embodiment, the impact screwdriver is provided with the protruding structure 122 on the rear cover 121 of the gear box 120, the first through hole 123 is arranged on the protruding structure 122 in a penetrating manner, and the front bearing 111 of the motor 110 is accommodated and carried by the first through hole 123, so that the rear cover 121 of the gear box 120 can be simultaneously used as a bearing seat of the motor 110. Therefore, a bearing seat is not required to be additionally arranged, the structure of the whole impact screwdriver is simplified, the overall length of the impact screwdriver is shortened, and the sustainability and the user experience are improved.

Specifically, in the present embodiment, the protruding structure 122 protrudes toward a side close to the motor 110 along the first direction a, and a length of the protruding structure 122 in the first direction a is greater than or equal to a length of the front bearing 111 in the first direction a. More specifically, as shown in fig. 3, the first through hole 123 is a stepped hole, and includes a first hole with a larger size and a second hole with a smaller size, the first hole is disposed near the motor 110, and the size of the first hole is matched with the size of the front bearing 111 for accommodating the front bearing 111; the second hole has a size smaller than that of the front bearing 111 and larger than that of the motor shaft 112 for the motor shaft 112 to pass through into the gear housing 120. In this embodiment, the entire portion of the front bearing 111 is disposed in the first through hole 123, and the rear cover 121 supports the front bearing 111 with high stability.

Further, the gear box 120 further includes a main shaft 124, the main shaft 124 extends along the first direction a, one end of the main shaft 124 close to the rear cover 121 is a rear end thereof, the rear end of the main shaft 124 is provided with a mounting hole 125 along the first direction a, and the front end of the motor shaft 112 is disposed in the mounting hole 125, so that the overall length of the impact screwdriver can be further shortened. It should be noted that the planetary gear mechanism is disposed in the main shaft 124, and the motor shaft 112 is in transmission connection with the sun gear of the planetary gear mechanism, so as to drive the sun gear to rotate. The planetary wheel mechanism still includes the planet wheel with the sun gear meshing, and in this embodiment, the quantity of planet wheel is three, and three planet wheel is along the circumference equipartition of sun gear.

Optionally, as shown with continued reference to fig. 3 and 4, the main shaft 124 includes a body portion 1241 and an annular protrusion 1242 that are connected in a stepped manner. The main body portion 1241 is configured to accommodate the planetary gear mechanism, and the main body portion 1241 is generally circular truncated cone-shaped, and has a fitting hole 125 formed along the first axis a, and the fitting hole 125 extends in the direction of the annular protrusion 1242 and penetrates through the annular protrusion 1242. And three planet wheel accommodating cavities are arranged in the main body part 1241 in the direction surrounding the assembling hole 125, and the three planet wheel accommodating cavities penetrate through the outer wall surface of the main body part 1241 along the radial direction of the main body part 1241. The three planet wheels are arranged in the three planet wheel accommodating cavities respectively, the front end and the rear end of the main body part 1241, which are positioned at two sides of the planet wheel accommodating cavities, are provided with three pin shaft holes 128, pin shafts penetrate through the pin shaft holes 128 corresponding to the front and the rear of the main body part 1241, and the planet wheels are rotatably connected in the planet wheel accommodating cavities through the pin shafts. And the part of the planet wheel protruding out of the planet wheel accommodating cavity is meshed with a gear ring of the planet wheel mechanism.

Further, the annular protrusion 1242 is in a circular truncated cone shape, and the size of the annular protrusion 1242 is smaller than that of the main body 1241, so that a bearing installation groove is formed by utilizing the outer wall surface of the annular protrusion 1242 and the rear end surface of the main body 1241, as shown in fig. 3, the gear box 120 further includes a main shaft lower bearing 126 therein, and the main shaft lower bearing 126 is sleeved on the annular protrusion 1242 of the main shaft 124 and is located in the bearing installation groove. The main shaft lower bearing 126 can effectively and stably support the main shaft 124, so that the main shaft 124 can stably rotate.

It should be noted that, in the present embodiment, since the protruding structure 122 protrudes away from the planetary gear mechanism, the size of the annular protrusion 1242 can be designed to be small, and the front end and the rear end of the main body 1241 have enough space to arrange the pin shaft holes 128, so that the pin shaft holes 128 and the annular protrusion 1242 are independent and do not interfere with each other.

Alternatively, as shown in fig. 5, a bearing installation cavity 127 communicated with the first through hole 123 is arranged inside the rear cover 121 of the gear box 120, the bearing installation cavity 127 includes an annular surface and a stop surface, the stop surface is arranged perpendicular to the first direction a, the annular surface is arranged around the first direction a, and one end of the stop surface, which is far away from the annular surface, is connected with the inner wall surface of the first through hole 123. The main shaft lower bearing 126 is arranged in the bearing installation cavity 127, the rear end face of the main shaft lower bearing 126 is abutted with the abutting face, and the outer wall face of the main shaft lower bearing 126 is abutted with the annular face.

Further alternatively, as shown in fig. 6, the rear cover 121 has a multi-step column shape as a whole, so that the wall thickness of the rear cover 121 is substantially the same everywhere, thereby reducing the space occupied by the rear cover 121 in the impact screwdriver, and reducing the self weight and the manufacturing cost. In order to secure the structural strength of the rear cover 121, a reinforcing boss structure may be provided at two steps of the rear cover 121.

In order to further shorten the overall length of the impact screwdriver, the rear cover 121 of the gear box 120 can be partially or integrally embedded into the stator of the motor 110, and the rear cover 121 is arranged into a multi-stage stepped column shape, so that the structure in the stator of the motor 110 can be effectively avoided, and the difficulty of embedding the rear cover 121 into the stator of the motor 110 is reduced.

Example two

The present embodiment provides an impact screwdriver, which also includes a working part 100, a handheld part 200 and a battery part 300, and the handheld part 200 and the battery part 300 are basically the same as those in the first embodiment except for the working part 100.

As shown in fig. 7, the working unit 100 includes a housing, a motor 110 and a gear box 120, an accommodating space is formed in the housing, and the motor 110 and the gear box 120 are both located in the housing. The motor 110 includes a motor shaft 112, and the motor shaft 112 extends in the first direction a in the accommodating space. The front end of the motor shaft 112 is sleeved with the front bearing 111, and the motor shaft 112 has two ends, wherein the end close to the gear box 120 is called a front end, and the end far away from the gear box 120 is called a rear end.

Specifically, in the present embodiment, as shown in fig. 8 and 9, the protruding structure 122 protrudes toward a side close to the motor 110 in the first direction a. Compared with the protruding structure 122 in the first embodiment, in the present embodiment, the protruding structure 122 has a shorter size, specifically, the length of the protruding structure 122 in the first direction a in the present embodiment is smaller than the length of the front bearing 111 in the first direction a. More specifically, in the present embodiment, the first through hole 123 is a through hole having a constant inner diameter, the rear end of the front bearing 111 is disposed in the first through hole 123, and the front end of the front bearing 111 protrudes out of the first through hole 123 and is disposed inside the gear housing 120.

Further, the gear box 120 further includes a main shaft 124, the main shaft 124 extends along the first direction a, one end of the main shaft 124 close to the rear cover 121 is a rear end thereof, the rear end of the main shaft 124 is provided with an assembly hole 125 along the first direction a, the front end of the motor shaft 112 is disposed in the assembly hole 125, and the front end of the front bearing 111 is also disposed in the assembly hole 125, so that the overall length of the impact screwdriver can be further shortened.

It should be noted that the planetary gear mechanism is disposed in the main shaft 124, and the motor shaft 112 is in transmission connection with the sun gear of the planetary gear mechanism, so as to drive the sun gear to rotate. The planetary wheel mechanism still includes the planet wheel with the sun gear meshing, and in this embodiment, the quantity of planet wheel is three, and three planet wheel is along the circumference equipartition of sun gear.

Optionally, as shown with continued reference to fig. 10 and 11, the main shaft 124 includes a body portion 1241 and an annular protrusion 1242 that are connected in a stepped manner. The main body portion 1241 is configured to accommodate the planetary gear mechanism, and the main body portion 1241 is generally circular truncated cone-shaped, and has a fitting hole 125 formed along the first axis a, and the fitting hole 125 extends in the direction of the annular protrusion 1242 and penetrates through the annular protrusion 1242. And three planet wheel accommodating cavities are arranged in the main body part 1241 in the direction surrounding the assembling hole 125, and the three planet wheel accommodating cavities penetrate through the outer wall surface of the main body part 1241 along the radial direction of the main body part 1241. The three planet wheels are arranged in the three planet wheel accommodating cavities respectively, the front end and the rear end of the main body part 1241, which are positioned in the planet wheel accommodating cavities, are provided with three pin shaft holes 128, pin shafts penetrate through the pin shaft holes 128 corresponding to the front and the rear of the main body part 1241, and the planet wheels are rotatably connected in the planet wheel accommodating cavities through the pin shafts. And the part of the planet wheel protruding out of the planet wheel accommodating cavity is meshed with a gear ring of the planet wheel mechanism.

Further, the annular protrusion 1242 is in a circular truncated cone shape, and the size of the annular protrusion 1242 is smaller than that of the main body 1241, so that a bearing installation groove is formed by utilizing the outer wall surface of the annular protrusion 1242 and the rear end surface of the main body 1241, as shown in fig. 7, the gear box 120 further includes a main shaft lower bearing 126 therein, and the main shaft lower bearing 126 is sleeved on the annular protrusion 1242 of the main shaft 124 and is located in the bearing installation groove. The main shaft lower bearing 126 can effectively and stably support the main shaft 124, so that the main shaft 124 can stably rotate. In order to further reduce the overall length of the impact screwdriver, the projections of the main shaft lower bearing 126 and the front bearing 111 on a plane parallel to the first direction a may at least partially overlap.

It should be noted that, compared to the annular protrusion 1242 in the first embodiment, in the present embodiment, since the front end of the front bearing 111 needs to be placed in the fitting hole 125, the size of the annular protrusion 1242 needs to be increased appropriately. Since the overall size of the main shaft 124 is not changed, the increase of the annular protrusion 1242 inevitably reduces the area of the end surface of the main body 1241 on which the pin hole 128 is provided, and as shown in fig. 10 and 11, the position of the pin hole 128 on the main body 1241 is not changed to attach the pin, and the annular protrusion 1242 is provided with an escape groove 129 for escaping the pin, and the escape groove 129 communicates with a part of the pin hole 128.

In order to ensure the structural strength of the main shaft 124, a rib may be provided at a position facing the escape groove 129 on the inner wall surface of the annular protrusion 1242, so that the structural strength of the annular protrusion 1242 is locally enhanced, thereby ensuring stable support of the front bearing 111 and ensuring the accuracy of the front bearing 111.

Continuing to refer to fig. 8, a bearing installation cavity 127 communicated with the first through hole 123 is arranged inside the rear cover 121 of the gear box 120, the bearing installation cavity 127 includes an annular surface and a resisting surface, the resisting surface is arranged perpendicular to the first direction a, the annular surface is arranged around the first direction a, and one end of the resisting surface, far away from the annular surface, is connected with the inner wall surface of the first through hole 123. The main shaft lower bearing 126 is arranged in the bearing installation cavity 127, the rear end face of the main shaft lower bearing 126 is abutted with the abutting face, and the outer wall face of the main shaft lower bearing 126 is abutted with the annular face.

Further alternatively, as shown with continued reference to fig. 9, the rear cover 121 may have an overall multi-step column shape, such that the wall thickness of the rear cover 121 may be substantially the same throughout to reduce the space occupied by the rear cover 121 within the impact screwdriver, as well as to reduce the self-weight and manufacturing cost. In order to ensure the same structure of the rear cover 121, a reinforcing boss structure may be provided at the two steps.

In order to further shorten the overall length of the impact screwdriver, the rear cover 121 of the gear box 120 can be partially embedded into the stator of the motor 110, and the rear cover 121 is arranged into a multi-stage stepped column shape, so that the structure in the stator of the motor 110 can be effectively avoided, and the difficulty of embedding part of the rear cover 121 into the stator of the motor 110 is reduced.

EXAMPLE III

The present embodiment provides an impact screwdriver, which also includes a working part 100, a handheld part 200 and a battery part 300, and the handheld part 200 and the battery part 300 are substantially the same as those in the first embodiment except for the working part 100.

As shown in fig. 12 and 13, the working unit 100 includes a housing, a motor 110, and a gear box 120, wherein an accommodating space is formed in the housing, and the motor 110 and the gear box 120 are both located in the housing. The motor 110 includes a motor shaft 112, and the motor shaft 112 extends in the first direction a in the accommodating space. The front end of the motor shaft 112 is sleeved with the front bearing 111, and the motor shaft 112 has two ends, wherein the end close to the gear box 120 is called a front end, and the end far away from the gear box 120 is called a rear end.

Specifically, in the present embodiment, as shown in fig. 14 and 15, the protruding structure 122 protrudes toward a side away from the motor 110 along the first direction a, and a length of the protruding structure 122 in the first direction a is greater than or equal to a length of the front bearing 111 in the first direction a. More specifically, as shown with continued reference to fig. 12 and 14, the first through-hole 123 is a through-hole having a constant inner diameter. In this embodiment, all of the front bearing 111 is disposed in the first through hole 123, and the rear cover 121 supports the front bearing 111 with high stability.

Further, the gear box 120 further includes a main shaft 124, the main shaft 124 extends along the first direction a, one end of the main shaft 124 close to the rear cover 121 is a rear end thereof, the rear end of the main shaft 124 is provided with an assembly hole 125 along the first direction a, and the front end of the motor shaft 112 and the protruding structure 122 are both disposed in the assembly hole 125, so that the overall length of the impact screwdriver can be further shortened.

Optionally, as shown with continued reference to fig. 12 and 13, the main shaft 124 includes a body portion 1241 and an annular protrusion 1242 that are connected in a stepped manner. The main body portion 1241 is configured to accommodate the planetary gear mechanism, and the main body portion 1241 is generally circular truncated cone-shaped, and has a fitting hole 125 formed along the first axis a, and the fitting hole 125 extends in the direction of the annular protrusion 1242 and penetrates through the annular protrusion 1242. And three planet wheel accommodating cavities are arranged in the main body part 1241 in the direction surrounding the assembling hole 125, and the three planet wheel accommodating cavities penetrate through the outer wall surface of the main body part 1241 along the radial direction of the main body part 1241. The three planet wheels are respectively arranged in the three planet wheel accommodating cavities, three pin shaft holes 128 are formed in the front end and the rear end of the main body part 1241, pin shafts penetrate through the pin shaft holes 128 corresponding to the front and the rear of the main body part, and the planet wheels are rotatably connected in the planet wheel accommodating cavities through the pin shafts. And the planet wheel protruding planet wheel accommodating cavity is meshed with a gear ring of the planet wheel mechanism.

Further, the annular protrusion 1242 is in a circular truncated cone shape, and the size of the annular protrusion 1242 is smaller than that of the main body 1241, so that a bearing installation groove is formed by utilizing the outer wall surface of the annular protrusion 1242 and the rear end surface of the main body 1241, as shown in fig. 12 and 13, the gear box 120 further includes a main shaft lower bearing 126 therein, and the main shaft lower bearing 126 is sleeved on the annular protrusion 1242 of the main shaft 124 and is located in the bearing installation groove. The main shaft lower bearing 126 can effectively and stably support the main shaft 124, so that the main shaft 124 can stably rotate.

In order to further reduce the overall length of the impact screwdriver, the projections of the main shaft lower bearing 126 and the front bearing 111 on a plane parallel to the first direction a may at least partially overlap. In the present embodiment, as shown with continued reference to fig. 12, the projections of the main shaft lower bearing 126 and the front bearing 111 on a plane parallel to the first direction a partially overlap.

Optionally, as shown in fig. 12, a bearing installation cavity 127 communicated with the first through hole 123 is provided inside the rear cover 121 of the gear box 120, the annular protrusion 1242 is located in the bearing installation cavity 127, the bearing installation cavity 127 includes an annular surface and an abutting surface, the abutting surface is disposed perpendicular to the first direction a, the annular surface is disposed around the first direction a, and one end of the abutting surface, which is far away from the annular surface, is connected to an inner wall surface of the first through hole 123. The main shaft lower bearing 126 is arranged in the bearing installation cavity 127, the rear end face of the main shaft lower bearing 126 is abutted with the abutting face, and the outer wall face of the main shaft lower bearing 126 is abutted with the annular face.

Further alternatively, the rear cover 121 has a multi-step column shape as a whole, so that the wall thickness of the rear cover 121 is substantially the same everywhere, thereby reducing the space occupied by the rear cover 121 in the impact screwdriver, and reducing the self weight and the manufacturing cost. In order to ensure the same structure of the rear cover 121, a reinforcing boss structure may be provided at the two steps.

It should be noted that the present embodiment is applicable to the motor 110 having a large diameter.

Further, the motor shaft 112 described in the above embodiments one to three may be either a bare shaft requiring additional assembly of the driving gear 113 as shown in fig. 3 and 7, or an integrated shaft formed with the driving gear 113 as shown in fig. 12, and in some embodiments, the integrated shaft contributes to further shortening the overall length of the impact screwdriver.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An impact screwdriver, comprising:

2. The impact screwdriver as recited in claim 1,

the gear box comprises a main shaft, the main shaft is arranged along a first direction a, an assembly hole is formed in the rear end, close to the rear cover, of the main shaft along the first direction a, and the end of the motor shaft extends into the assembly hole.

3. The impact screwdriver as recited in claim 2,

the protruding structure is arranged in a protruding mode towards the direction close to the motor, the front end structure of the front bearing is arranged in the assembling hole, and the outer wall surface of the front end of the front bearing is abutted to the inner wall surface of the assembling hole;

4. The impact screwdriver as recited in claim 2,

the protruding structure is arranged in a protruding mode in the direction far away from the motor, the protruding structure is inserted into the assembling hole, and the front bearing is arranged in the first through hole.

5. The impact screwdriver according to claim 3 or 4,

the gear box further comprises a main shaft lower bearing;

6. The impact screwdriver as recited in claim 5,

the projections of the under spindle bearing and the front bearing on a plane parallel to the first direction a at least partially overlap.

7. The impact screwdriver as recited in claim 6, wherein said lower spindle bearing and said forward bearing are embedded within a stator of said motor.

8. The impact screwdriver as recited in claim 2,

the gearbox further comprises a planetary wheel, the main shaft comprises a main body part and a ring convex part which are connected in a stepped columnar mode, a pin shaft hole is formed in the main body part, and a pin shaft of the planetary wheel penetrates through the pin shaft hole.

9. The impact screwdriver as recited in claim 8,

the ring convex part is provided with an avoiding groove for avoiding the pin shaft, and the avoiding groove is communicated with part of the pin shaft hole.

10. The impact screwdriver as recited in claim 1,

the motor shaft is an integral shaft formed with a drive gear.