CN207364214U

CN207364214U - Electric tool

Info

Publication number: CN207364214U
Application number: CN201720650762.5U
Authority: CN
Inventors: 刘强
Original assignee: Suzhou Dake Machinery Co Ltd
Current assignee: Suzhou Dake Machinery Co Ltd
Priority date: 2017-06-06
Filing date: 2017-06-06
Publication date: 2018-05-15
Anticipated expiration: 2027-06-06

Abstract

The utility model discloses a kind of electric tool,Including motor,Motor shaft,Output shaft and clutch,Motor shaft is equipped with power gear,Output shaft is equipped with mating gear,Wherein clutch includes jackshaft,The Transmission gear engaged arranged on jackshaft and with mating gear,Arranged on the clutch of jackshaft,The one-stage gear engaged to the periphery and with power gear arranged on the week of clutch,Clutch has relative to the fixed first state of one-stage gear and the second state that can be rotated relative to first gear,Clutch has a plurality of clutch forks for the axial end face that body is arranged on the body of jackshaft interference fit and circumferential annular space,The inner ring of one-stage gear is interval with plurality of grooves in a ring,During first state,Clutch fork coordinates with groove,During the second state,Clutch fork produces elastic deformation relative to body,Clutch fork is disengaged with groove.The clutch of the electric tool is simple in structure, safety and reliability higher.

Description

Electric tool

Technical field

It the utility model is related to a kind of electric tool.

Background technology

In general, the clamping stagnation of drill bit occurs in drill kind tool in use, so as to produce excessive reverse torsion transmission To user, infliction of body is produced to user.To solve the above problems, those skilled in the art is on drill type electric tool Torsion Machine guarding was equipped with, the clutch apparatus being such as installed on drill kind tool, so as to avoid drill kind tool from using During the excessive reverse torsion that is produced by the clamping stagnation of drill bit pass to user, but be currently used in the clutch on drill kind tool Device apparatus structure is complicated, craftsmanship is poor and safety and reliability is all relatively low.

Utility model content

The purpose of this utility model is to provide a kind of electric tool, the clutch of the electric tool is simple in structure, and Safety and reliability higher.

To realize above-mentioned purpose of utility model, one embodiment of the utility model provides a kind of electric tool, including motor, Driven by the motor to produce the motor shaft, output shaft, the work head arranged on the output shaft of rotary motion, the motor shaft Clutch is equipped between the output shaft, the motor shaft is equipped with power gear, and the output shaft is equipped with mating tooth Wheel, wherein the transmission tooth that the clutch includes jackshaft, is fixed at the jackshaft and engaged with the mating gear Take turns, be fixed at the clutch of the jackshaft, to the periphery and with the power gear engaged arranged on the week of the clutch One-stage gear, and the clutch has relative to the fixed first state of the one-stage gear and relative to the level-one The second state that gear can rotate, the clutch have and the body of jackshaft interference fit and circumferential annular Interval is arranged on a plurality of clutch forks of the axial end face of the body, and the inner ring of the one-stage gear is interval with plural number in a ring A groove, during first state, the clutch fork coordinates with the groove, when the anti-twisted power that the output shaft is subject to is more than predetermined value When, the clutch fork produces elastic deformation relative to body, and the clutch fork is disengaged with the groove, at this time at the clutch When the second state.

Further as the utility model embodiment is improved, and the clutch fork is in the axis perpendicular to the jackshaft Cross section on direction is isosceles trapezoid, and the cross section of the groove is also the isosceles trapezoid being adapted with the clutch fork.

Further as the utility model embodiment is improved, and the one-stage gear has an endoporus, and the groove is from institute State endoporus along the radial direction of the endoporus to the direction at the center away from the endoporus to extend, the clutch fork is disengaged with the groove It must meet the following conditions：N_Bullet≤ F1 (cos θ-μ sin θs)/(sin θ+μ cos θ), and Y_max>=△, wherein Y_max=(N_BulletL³)/ (3EI), I=bh³/ 12, Y_maxFor clutch fork maximum defluxion, N_BulletCaused elastic force when producing elastic deformation for clutch fork, F1 are Clutch fork act on the tooth rim of the one-stage gear to tangential force, the trapezoid cross section of clutch fork have 2 bottom points, top and From the inclined-plane that 2 bottom points extend to top, the two bottoms point defines a straight line, formed by the inclined-plane and the straight line Angle is θ, friction coefficient of the μ between the one-stage gear and the clutch fork, and L is the stress point of clutch fork to supporting point Equivalent distances, E is the elasticity modulus of clutch fork, and I is the moment of inertia of clutch fork, and b be clutch fork rectangular equivalent width, h for from Fork rectangular equivalent height is closed, △ is the half of the difference in the aperture of the endoporus of clutch fork outside diameter and one-stage gear.

Further as the utility model embodiment is improved, and is had between the endoporus of the clutch fork and the jackshaft There is gap, space is provided with the deformation for the clutch fork.

Further as the utility model embodiment is improved, and positioning disk, the positioning are additionally provided with the jackshaft The end face of disk fits with the Transmission gear, and the other end of the positioning disk has stage portion, and the one-stage gear supports The stage portion is connected to, and the one-stage gear can be rotated operatively relative to positioning disk.

Further as the utility model embodiment is improved, and the clutch fork and groove are disposed as 6.

Further as the utility model embodiment is improved, and the clutch fork and groove are uniformly distributed circumferentially.

Further as the utility model embodiment is improved, and the clutch fork includes being coupled or disengaging with the groove Mating part and the connecting portion of the connection mating part and body, the outside diameter of the mating part be more than the outer of the connecting portion Footpath.

Further as the utility model embodiment is improved, and the mating part and the circumferentially-spaced cantilever of connecting portion are set In the body.

Further as the utility model embodiment is improved, and the body is equipped with stopper section, the stopper section Limit the axial movement of the one-stage gear.

Further as the utility model embodiment is improved, and the output shaft is equipped with the first mating gear and second Gear is coupled, the Transmission gear includes the first Transmission gear and the second Transmission gear, and the electric tool can operatively be made The first mating gear is engaged with the first Transmission gear or the second mating gear is engaged with the second Transmission gear.

Further as the utility model embodiment is improved, and second Transmission gear is located at the clutch and institute State between the first Transmission gear.

Further as the utility model embodiment is improved, the first mating gear and the second mating gear one Shaping is set.

Further as the utility model embodiment is improved, and the electric tool is hand-held type electric tool, described Hand-held type electric tool includes the collet being arranged on the output shaft, and the work head can be operatively installed on the collet Or pulled down from collet.

Compared with prior art, the beneficial effects of the utility model are：Technical solution provided by the utility model, works as electricity When power driven tools work normally, the groove on clutch fork and one-stage gear coordinates, and motor shaft passes through power gear and one-stage gear Engagement transfers power to one-stage gear, since the groove of clutch fork and one-stage gear coordinates, so that one-stage gear drives clutch Device and jackshaft rotate, and then jackshaft drives the Transmission gear above it to rotate, and Transmission gear is engaged with mating gear, so that Mating gear is set to drive output shaft to rotate, it is final to drive the work of work head.And when work head be stuck when, jackshaft pass to from It is excessive to close the anti-twisted power of fork, clutch fork produces deformation, and clutch fork is disengaged with groove, and one-stage gear will be unable to drive clutch to turn Dynamic, one-stage gear non-loaded rotation, output shaft under the drive of power gear stop operating, so as to play beyond setting torque value The effect that can be protected, prevents user's body to be subject to unexpected injury.The clutch of the electric tool, a plurality of clutch forks are circumferential Annular space is arranged on the axial end face of the body, that is to say, that clutch fork is the structure that cantilever is arranged at body, and normal work When making, clutch fork is coupled with groove, and when anti-twisted power is excessive, clutch fork is deformed to be disengaged with groove, the clutch structure Simply, and safety and reliability higher.

Brief description of the drawings

Fig. 1 is the phantom of electric tool in the utility model embodiment；

Fig. 2 is the sectional view of the clutch of electric tool in the utility model embodiment；

Fig. 3 is I-I sectional views in Fig. 2；

Fig. 4 is the schematic diagram of the jackshaft and Transmission gear in Fig. 2 clutches；

Fig. 5 is the front view of clutch in Fig. 2 clutches；

Fig. 6 is the transverse sectional view of clutch in Fig. 5；

Fig. 7 is the front view of the one-stage gear in Fig. 2 clutches；

Fig. 8 is the stress diagram of clutch in Fig. 2 clutches；

Fig. 9 is clutch and one-stage gear cooperation schematic diagram in Fig. 2 clutches；

Figure 10 is the stress diagram between clutch and one-stage gear in Fig. 2 clutches；

Figure 11 is the force analysis figure of clutch and one-stage gear in Figure 10；

Figure 12 is the schematic diagram of positioning disk in Fig. 2.

Embodiment

The utility model is described in detail below with reference to embodiment shown in the drawings.But these embodiment party Formula is not intended to limit the utility model, structure that those of ordinary skill in the art are made according to these embodiments, method or Conversion functionally is all contained in the scope of protection of the utility model.

In each diagram of the application, for the ease of illustration, structure or partial some sizes can be relative to other knots Structure or part are exaggerated, and therefore, are only used for the basic structure of the theme of diagram the application.

In addition, it is used herein for example " on ", " top ", " under ", the term of the representation space relative position such as " lower section " be A unit as shown in the drawings or feature are described relative to another unit or feature for the purpose easy to explanation Relation.The term of relative space position can be intended to include equipment in use or work in addition to orientation shown in figure not Same orientation.If for example, by figure equipment overturn, be described as being located at other units or feature " lower section " or " under " Unit will be located at other units or feature " top ".Therefore, exemplary term " lower section " can include above and below both Orientation.Equipment can otherwise be directed (be rotated by 90 ° or other directions), and correspondingly explain it is used herein with it is empty Between relevant description.Above-mentioned term is only used for these description objects being distinguished from each other out, this protection without departing from this application Scope.

Furthermore, it should be appreciated that although the grade of term first, second can be used to describing herein various elements or Structure, but these are described the limitation that object should not be restricted by above-mentioned term.Above-mentioned term be only used for by these description objects that This is distinguished.For example, the first Transmission gear can be referred to as the second Transmission gear, equally, the second Transmission gear can also be claimed Make the first Transmission gear, this protection domain without departing from this application.

As shown in Figure 1, Figure 2, Figure 3 and Figure 4, specific embodiment of the utility model discloses a kind of electric tool, the electricity Power driven tools include motor, are driven by motor to produce the motor shaft 20, output shaft 22, the work arranged on output shaft 22 of rotary motion Head, is equipped with clutch between motor shaft 20 and output shaft 22, motor shaft 20 is equipped with power gear 24, and output shaft 22 is equipped with Gear 26 is coupled.The electric tool further includes reduction box 23 and middle cover 25.

Clutch include jackshaft 28, be fixed at the Transmission gear of jackshaft 28, be fixed at jackshaft 28 from Clutch 32 and all one-stage gears 34 to the periphery arranged on clutch 32, wherein Transmission gear are engaged with mating gear 26, level-one Gear 34 is engaged with power gear 24.In addition, clutch 32 has first state and the second state, during first state, clutch 32 is fixed relative to one-stage gear 34, and during the second state, clutch 32 can rotate relative to one-stage gear 34.Into One step is with reference to shown in Fig. 5 to Fig. 7, specifically, clutch 32 has the body 36 being interference fitted with jackshaft 28 and circumferential ring Shape interval is arranged on a plurality of clutch forks 38 of the axial end face of body 36, and the inner ring of one-stage gear 34 is interval with again in a ring Several grooves 40, during first state, clutch fork 38 coordinates with groove 40, and when the anti-twisted power that output shaft 22 is subject to be more than it is predetermined During value, clutch fork 38 produces elastic deformation relative to body 36, and clutch fork 38 is disengaged with groove 40, and clutch 32 is at this time During the second state.

In this preferred embodiment, when electric tool works normally, clutch fork 38 is matched somebody with somebody with the groove 40 on one-stage gear 34 Close, motor shaft 20 transfers power to one-stage gear 34 by power gear 24 with engaging for one-stage gear 34, due to clutch fork 38 coordinate with the groove 40 of one-stage gear 34, so that one-stage gear 34 drives clutch 32 and jackshaft 28 to rotate, so that it is middle Axis 28 drive its above Transmission gear rotate, Transmission gear with mating gear 26 engage so that be coupled gear 26 drive it is defeated Shaft 22 rotates, final to drive the work of work head.And when the head that works is stuck, jackshaft 28 passes to the anti-of clutch fork 38 Torsion is excessive, and clutch fork 38 produces deformation, and clutch fork 38 is disengaged with groove 40, and one-stage gear 34 will be unable to drive 32 turns of clutch Dynamic, the non-loaded rotation under the drive of power gear 24 of one-stage gear 34, output shaft 22 stops operating, so as to play beyond setting The effect that torque value can be protected, prevents user's body to be subject to unexpected injury.

The clutch of the electric tool, a plurality of circumferential annular spaces of clutch fork 38 are arranged on the axial end of body 36 Face, that is to say, that clutch fork 38 is the structure that cantilever is arranged at body 36, and during normal work, clutch fork 38 is matched somebody with somebody with groove 40 Connect, when anti-twisted power is excessive, clutch fork 38 is deformed to be disengaged with groove 40, and the clutch is simple in structure, and security and Reliability higher.

Cross section of the clutch fork 38 on the axis direction perpendicular to jackshaft 28 is trapezoidal, the cross section of groove 40 It is trapezoidal to be adapted with clutch fork 38.When the head that works is stuck, the anti-twisted power that jackshaft 28 passes to clutch fork 38 is excessive, The trapezoidal inclined plane 39 of clutch fork 38 slides along the trapezoidal inclined plane 37 of groove 40, when the amount of deflection of clutch fork 38 reaches certain value, one Level gear 34 cannot drive clutch fork 38 to rotate again, and clutch fork 38 is disengaged with groove 40.Further, clutch fork 38 is vertical It is isosceles trapezoid in the cross section on the axis direction of jackshaft 28, the cross section of groove 40 is also adapted with clutch fork 38 Isosceles trapezoid.

Specifically, one-stage gear 34 has endoporus 35, groove 40 is from endoporus 35 along the radial direction of endoporus 35 to away from endoporus 35 Center direction extension, with further reference to Fig. 8 to Figure 11, Equation f can be listed₁=μ xN1；FX=F1cos θ-f1-N_Bulletsinθ； F_y=N1-F1sin θ-N_Bulletcosθ；F₁=Mn X 4/ ((D+d) X Z)；It need to meet condition when clutch 32 and groove 40 disengage F_y=0 and F_x>=0, so as to solve N_Bullet≤F₁(cos θ-μ sin θs)/(sin θ+μ cos θ), wherein f₁For the groove of one-stage gear 34 Frictional force between 40 trapezoidal inclined plane 37 and the trapezoidal inclined plane 39 of clutch fork 38, μ are the trapezoidal of the groove 40 of one-stage gear 34 Friction coefficient between inclined-plane 37 and the trapezoidal inclined plane of clutch fork 38 39, F₁The tooth rim of one-stage gear 34 is acted on for clutch fork 38 To tangential force, 2 bottom points, top and extend in addition, the trapezoid cross section of clutch fork 38 has from 2 bottom points to top oblique Face, 2 bottom points define a straight line, and inclined-plane is θ with angle formed by straight line；Mn is de- with groove 40 for default clutch fork 38 The torsion opened, D are the outside diameter of clutch fork 38, and d is the aperture of the endoporus 35 of one-stage gear 34, and Z is the fork number of clutch fork 38.

Also need to meet another condition Y when clutch 32 and groove 40 disengage_max>=△, wherein Y_max=(N_PressureL³)/ (3EI), I=bh³/ 12, △=(D-d)/2, Y_maxFor clutch fork maximum defluxion, N_PressureClutch 32 is put on for one-stage gear 34 On radial load, N_PressureCaused elastic force N when producing elastic deformation with clutch fork 38_BulletEqual, L is that the stress point of clutch fork 38 arrives The equivalent distances of supporting point, E are the elasticity modulus of clutch fork 38, and I is the moment of inertia of clutch fork 38, and b is 38 rectangle of clutch fork etc. Width is imitated, h is 38 rectangular equivalent of clutch fork height, and △ is 38 outside diameter of clutch fork and the aperture of the endoporus 35 of one-stage gear 34 The half of difference.

In this preferred embodiment, clutch fork 38 is cantilever design, and the check of 38 shear strength of clutch fork is as follows, according to square Shape cantilever beam design formula σ max=Mmax/W W=bh²/ 6, and when σ max are less than the anti-shearing strong of 38 material therefor of clutch fork At 0.6-0.8 times of degree, you can meet the requirements.Wherein, Mmax is the maximal bending moment that clutch fork 38 is born, and W is 38 square of clutch fork Tee section modulus, σ max are the maximum shear stress that clutch fork 38 is born.

In addition, referring again to Fig. 2 and Fig. 5, there is gap between the endoporus 41 and jackshaft 28 of clutch fork 38, so as to be clutch The deformation of fork 38 provides space.The body 36 of clutch 32 is interference fitted with jackshaft 28, so as to work as clutch fork 38 and one When level gear 34 coordinates, motor shaft 20 rotate can by power gear 24 and one-stage gear 34 engage transfer power to from Clutch 32, drives jackshaft 28 to rotate, and then jackshaft 28 drives the Transmission gear above it to rotate.

In this preferred embodiment, clutch fork 38 and groove 40 are disposed as 6.Certainly, clutch fork 38 and groove 40 also may be used To be arranged to other quantity.Preferably, clutch fork 38 and groove 40 are uniformly distributed circumferentially, it is of course also possible to be arranged to edge The even distribution of circumferential asymmetry.

In addition, clutch fork 38 includes the mating part 50 for being coupled or disengaging with groove 40 and is connected mating part 50 and body 36 connecting portion 52, the outside diameter of mating part 50 are more than the outside diameter of connecting portion 52.Further, the internal diameter and connecting portion of mating part 50 52 internal diameter is roughly the same.It is arranged such so that 38 structure of clutch fork is not only simple, and causes matching somebody with somebody for clutch fork 38 and groove 40 Close or disengage and is relatively reliable.Further, mating part 50 and the circumferentially-spaced cantilever of connecting portion 52 are arranged on body 36.

Specifically, referring again to Fig. 1 and Fig. 2, output shaft 22 is equipped with the first mating gear 42 and second and gear 44 is coupled, and passes Passing gear includes the first Transmission gear 46 and the second Transmission gear 48, electric tool can operatively be made the first mating gear 42 with First Transmission gear 46 engages or the second mating gear 44 is engaged with the second Transmission gear 48.When the first mating gear 42 and the When one Transmission gear 46 engages, electric tool is in high gear；When the second mating gear 44 is engaged with the second Transmission gear 48 When, electric tool is in low gear.Work so as to fulfill electric tool double speed, certainly, Transmission gear and mating gear also may be used Only to set one, or it is arranged to other quantity.

Further, the first mating gear 42 and second is coupled gear 44 and is integrally formed setting.That is the first mating It is duplicate gear that gear 44, which is coupled, in gear 42 and second, and duplicate gear passes through internal spline 47 and external splines 49 and 22 phase of output shaft Connection, so that the rotary power of motor has been passed to output shaft 22, drives the work of work head.

This preferred embodiment, electric tool are hand-held type electric tool, and hand-held type electric tool includes being arranged on output shaft 22 On collet 60, work head can be operatively installed on collet 60 or be pulled down from collet 60.Specifically, the electronic work of hand-held class Have for electric drill, correspondingly, work head is drill bit.

With further reference to Fig. 2, Fig. 5 and Figure 12, positioning disk 54, the end face 55 of positioning disk 54 are additionally provided with jackshaft 28 Fit with Transmission gear, specifically, the end face 55 of positioning disk 54 and the end face 33 of Transmission gear fit, positioning disk 54 Other end has stage portion 56, and one-stage gear 34 is connected to stage portion 56, and gap between one-stage gear 34 and stage portion 56 Coordinate, such one-stage gear 34 can be rotated operatively relative to positioning disk 54.Furthermore clutch 32 is with positioning disk 54 in The axial direction of countershaft 28 has certain interval, and body 36 and the jackshaft 28 of clutch 32 are interference fitted.Jackshaft 28 has axis Shoulder 43, the body 36 of clutch 32 are resisted against shaft shoulder portion 43.In addition, 57 interference of endoporus of positioning disk 54 is sheathed on jackshaft On 28.

Further, body 36 is equipped with stopper section 58, and stopper section 58 is used for the axial shifting for limiting one-stage gear 34 It is dynamic.One-stage gear 34 is located between stopper section 58 and the stage portion 56 of positioning disk 54.

It should be appreciated that although the present specification is described in terms of embodiments, not each embodiment only includes one A independent technical solution, this narrating mode of specification is only that those skilled in the art will should say for clarity For bright book as an entirety, the technical solution in each embodiment may also be suitably combined to form those skilled in the art can With the other embodiment of understanding.

The a series of tool for describing the feasibility embodiment only for the utility model in detail of those listed above Body illustrates that they are simultaneously not used to limitation the scope of protection of the utility model, all to be made without departing from the utility model skill spirit Equivalent implementations or change should be included within the scope of protection of this utility model.

Claims

1. a kind of electric tool, including motor, driven by the motor to produce the motor shaft of rotary motion, output shaft, be arranged on The work head of the output shaft, is equipped with clutch between the motor shaft and the output shaft, the motor shaft is equipped with dynamic Powershift gear, the output shaft are equipped with mating gear, it is characterised in that the clutch includes jackshaft, is fixed at institute State jackshaft and with it is described mating gear engage Transmission gear, be fixed at the jackshaft clutch, arranged on it is described from The one-stage gear that the week of clutch engages to the periphery and with the power gear, and the clutch has relative to the level-one tooth Fixed first state and the second state that can be rotated relative to the one-stage gear are taken turns, the clutch has A plurality of clutch forks of the axial end face of the body are arranged on the body of jackshaft interference fit and circumferential annular space, The inner ring of the one-stage gear is interval with plurality of grooves in a ring, and during first state, the clutch fork is matched somebody with somebody with the groove Close, when the anti-twisted power that the output shaft is subject to is more than predetermined value, the clutch fork produces elastic deformation relative to body, described Clutch fork is disengaged with the groove, when the clutch is in the second state at this time.

2. electric tool according to claim 1, it is characterised in that the clutch fork is in the axis perpendicular to the jackshaft Cross section on line direction is isosceles trapezoid, and the cross section of the groove is also the isosceles trapezoid being adapted with the clutch fork.

3. electric tool according to claim 2, it is characterised in that the one-stage gear has endoporus, and the groove is certainly The endoporus extends along the radial direction of the endoporus to the direction at the center away from the endoporus, and the clutch fork takes off with the groove Open palpus and meet the following conditions：N_Bullet≤ F1 (cos θ-μ sin θs)/(sin θ+μ cos θ), and Y_max>=△, wherein Y_max=(N_BulletL³)/ (3EI), I=bh³/ 12, Y_maxFor clutch fork maximum defluxion, N_BulletCaused elastic force when producing elastic deformation for clutch fork, F1 are Clutch fork act on the tooth rim of the one-stage gear to tangential force, the trapezoid cross section of clutch fork have 2 bottom points, top and From the inclined-plane that 2 bottom points extend to top, the two bottoms point defines a straight line, formed by the inclined-plane and the straight line Angle is θ, friction coefficient of the μ between the one-stage gear and the clutch fork, and L is the stress point of clutch fork to supporting point Equivalent distances, E are the elasticity modulus of clutch fork, and I is the moment of inertia of clutch fork, and b is clutch fork rectangular equivalent width, and h is clutch Rectangular equivalent height is pitched, △ is the half of the difference in the aperture of the endoporus of clutch fork outside diameter and one-stage gear.

4. electric tool according to claim 1, it is characterised in that between the endoporus of the clutch fork and the jackshaft With gap, space is provided with the deformation for the clutch fork.

5. electric tool according to claim 1, it is characterised in that positioning disk is additionally provided with the jackshaft, it is described fixed The end face of position disk fits with the Transmission gear, and the other end of the positioning disk has stage portion, the one-stage gear The stage portion is connected to, and the one-stage gear can be rotated operatively relative to positioning disk.

6. electric tool according to claim 1, it is characterised in that the clutch fork and groove are disposed as 6.

7. electric tool according to claim 6, it is characterised in that the clutch fork and groove circumferentially uniformly divide Cloth.

8. electric tool according to claim 6, it is characterised in that the clutch fork includes being coupled or taking off with the groove The mating part opened and the connecting portion of the connection mating part and body, the outside diameter of the mating part are more than the outer of the connecting portion Footpath.

9. electric tool according to claim 8, it is characterised in that the mating part and the circumferentially-spaced cantilever of connecting portion Arranged on the body.

10. electric tool according to claim 6, it is characterised in that the body is equipped with stopper section, the backstop Portion limits the axial movement of the one-stage gear.

11. electric tool according to claim 1, it is characterised in that the output shaft be equipped with first mating gear and Second mating gear, the Transmission gear include the first Transmission gear and the second Transmission gear, and the electric tool can be operated Ground makes described first to be coupled, and gear is engaged with the first Transmission gear or the second mating gear is engaged with the second Transmission gear.

12. electric tool according to claim 11, it is characterised in that second Transmission gear is located at the clutch Between first Transmission gear.

13. electric tool according to claim 11, it is characterised in that the first mating gear and the second mating gear It is integrally formed setting.

14. electric tool according to any one of claim 1 to 13, it is characterised in that the electric tool is hand-held Type electric tool, the hand-held type electric tool include the collet being arranged on the output shaft, and the work head can be by operatively It is installed on the collet or is pulled down from collet.