TWI648113B - Hammer drill - Google Patents

Abstract

The hammer drill of the present invention mainly comprises a body, a driving shaft, a hammering member, a fixing ring member, an elastic member and a tool head. The driving shaft is provided with a sliding groove and a connecting groove, and the hammering member is disposed on the hammering member. a through hole, and a sliding bead is disposed in the through hole, and the fixing ring is sleeved on the outside of the hammering member, so that the sliding ball abuts against the sliding groove of the driving shaft and the connecting groove, and the hammering piece and the fixing ring piece An elastic member is further disposed, and the elastic member pushes against the hammering member, so that the sliding ball of the hammering member is closely attached to the sliding groove, so that the hammering member repeats along the axial direction along with the shape of the sliding groove. The displacement, which is converted into a linear reciprocating motion by the rotary motion, causes the tool head to simultaneously perform the rotation and hammering action.

Description

Hammer drill

The present invention relates to a hammer drill that primarily includes the function of hammering and a drill bit.

The main structure of the hammer drill on the market includes a crankshaft and a motor. The motor rotates to drive the crankshaft to rotate. Then, by the characteristics of the crankshaft, the tool head coupled to the crankshaft can be displaced along the axial direction, and the motor is directly connected to the tool. The head transmits the kinetic energy of the circumferential rotation to complete the hammer drill with both hammering and drilling functions.

Japanese Patent Laid-Open No. 2006-142459 discloses a hammer drill which mainly controls a crankshaft by a motor so that the tool head can be reciprocally displaced along the axial direction, and the motor is connected to the helical gear, and the helical gear can enable the tool head along the Rotation in the circumferential direction achieves the effect of being able to rotate the tool head in the circumferential direction and also to be displaced in the axial direction.

However, in order to enable the tool head to rotate both circumferentially and axially, the hammer drill generally needs to divide the overall structure into two groups, one of which transmits the power of the motor to the tool head to control its circumferential direction. Rotating, while another set of power transmission structure transmits the power of the motor to the crankshaft, and then the hammer is controlled by the crankshaft to repeatedly hammer it along the axial direction. The complicated structure not only makes the hammer drill assembly difficult, but also This has led to a significant increase in costs.

In view of this, it is indeed necessary to solve the aforementioned lack of assembly difficulties due to complicated structures.

The object of the present invention is to solve the problem that the hammer drill is difficult to assemble due to complicated structure and the cost is increased.

To achieve the foregoing objects, the present invention is a hammer drill comprising:

a body having a motor;

a driving shaft having an opposite end and a striking end, wherein the driving end extends to the striking end in an axial direction, the driving end is provided with a matching hole, and the driving shaft is coupled to the motor to enable the driving The driving shaft is rotatable in the circumferential direction, and the driving shaft is provided with at least two symmetrically arranged sliding grooves and at least two symmetrically arranged connecting grooves, each of the sliding grooves respectively having a first end and a second end, the first The end of the connecting groove is closer to the driving end, and the two ends of each connecting groove are respectively connected to the first end of one of the sliding grooves and the second end of the other sliding groove, so that the sliding groove and each of the sliding grooves Connecting grooves are alternately connected and surround the drive shaft;

a hammering member is sleeved on the driving shaft, and the hammering member is provided with at least two symmetrically arranged through holes, and each of the through holes is respectively provided with a sliding bead;

a fixing ring member is fixedly sleeved on the hammering member, and an inner wall surface of the fixing ring member abuts against each of the sliding beads, so that each sliding ball is limited to each of the through holes and abuts against the driving shaft Each of the sliding grooves;

An elastic member is disposed between the hammering member and the fixing ring member, so that the hammering member is pushed along the axial direction in a direction opposite to the fixing ring member, and each of the sliding beads is respectively abutted against Each of the sliding grooves;

a tool head having a connecting section and a working section, wherein the connecting section is a polyhedron and is connected with a matching hole of the driving shaft, and the working section is provided with a connecting working head, and the connecting section has a push between the working section and the working section Adjacent to the ring wall, the pushing ring wall abuts against the hammering member.

In a preferred embodiment, the driving shaft has a positioning 环绕 around the driving shaft, and the positioning 垣 has a detachment space from each of the sliding grooves, and has a fixed front shell and a conversion group. The front cover is sleeved on the fixed ring member, and the fixed front case is provided with at least two displacement holes, the conversion set has a change ring member, and the change ring member is sleeved on the fixed front case, and the The shifting ring member has at least two pushing feet, and each of the pushing legs is slidably inserted into each of the displacement holes, and the shifting ring member is displaced along the axial direction, so that each of the pushing ring members is worn The displacement holes are pushed against the hammering member along the axial direction, so that the hammering member is displaced along the axial direction toward the fixing ring member, and the sliding beads located in each of the through holes are along the axial direction. Move to the detachment space.

In a preferred embodiment, the conversion set further has a rotating ring sleeved on the fixed front shell, the rotating ring has a ring inner surface facing each of the displacement holes, and the inner surface of the ring has along the a two-sided trapezoidal slope provided on a circumferential surface of the rotating ring, and each of the trapezoidal slopes has a lower end connecting the inner surface of the ring and a top end away from the inner surface of the ring, and the conversion ring has two extending ears, and the two extending ears Relying on the two trapezoidal slopes respectively, the pushing ring of the changing ring member is placed in each of the displacement holes, so that the changing ring member cannot rotate in the circumferential direction, and by rotating the rotating ring, The different heights of the two trapezoidal slopes correspond to the two extended ears of the rotating ring, and the moving ring member is moved toward the motor along the axial direction, and each of the pushing feet pushes against the striking portion of the hammering member, so that the The hammering member moves toward the motor along the axial direction, and the hammering member drives the respective balls to move along the axial direction to the detachment space.

In a preferred embodiment, the motor has a drive shaft that is rotatable in the circumferential direction, the drive shaft is provided with an external tooth, and a planetary gear set is disposed in the body, the planetary gear set has a fixing member, a ring gear and three planetary gears, the fixing member is fixedly mounted in the body and is provided for the transmission shaft to pass therethrough, and the fixing member has a plurality of buckle grooves, and the ring gear is fixed to the fixing In the device, each of the planetary gears meshes with the ring gear, and the driving shaft is provided with three power transmission slots, each of the power transmission slots respectively accommodating one of the planetary gears, and the transmission shaft passes through the driving shaft The driving end meshes with each of the planetary gears, thereby driving each of the planetary gears to rotate, so that the driving shaft can rotate in the circumferential direction.

In a preferred embodiment, the outer peripheral surface of the hammer has a first limiting surface, and the inner peripheral surface of the fixing ring has a second limiting surface, the second limiting surface is provided to abut the first The limit surface in turn prevents the hammer member from rotating along the circumference.

In a preferred embodiment, the hammer member has a striking portion at one end away from the motor, the striking portion has a first abutting surface facing the motor, and the fixing ring member has a fixing portion near one end of the motor. The fixing portion has a second abutting surface facing the first abutting surface, and one end of the elastic member abuts against the first abutting surface, and the other end of the elastic member abuts against the second abutting surface.

In a preferred embodiment, the connecting section of the tool head is a cylinder.

Thereby, the present invention achieves the hammering action by the sliding groove provided on the driving shaft, the sliding ball of the hammering member, the fixing ring member and the elastic member, and the driving shaft can simultaneously drive the tool head to rotate, so that The present invention converts only the rotary motion into a linear reciprocating motion, so that the hammer drill completes the hammering action of the reverse displacement along the axial direction and the rotational motion along the circumferential direction.

Referring to Figures 1 to 7, the present invention is a hammer drill comprising:

A body 10 has a casing 11 for forming an accommodating space 111. The accommodating space 111 is provided with a motor 12 having a transmission shaft 121 rotatable in the circumferential direction. The transmission shaft 121 is mounted on the transmission shaft 121. With external teeth;

A planetary gear set 20 is disposed in the accommodating space 111. The planetary gear set 20 has a fixing member 21, a ring gear 22, and three planetary gears 23. The fixing member 21 is fixedly mounted in the accommodating space 111. The fixing shaft 21 has a plurality of fastening grooves 211. The ring gear 22 has a plurality of fixing ribs 221, and the fixing ribs 221 are respectively fixed to the fastening grooves 211. Inner, and each of the planetary gears 23 meshes with the ring gear 22;

A driving shaft 30 has an opposite driving end 30A and a striking end 30B. The driving end 30A is near one end of the motor 12, and the striking end 30B is opposite to the other end of the driving end 30A. The driving end 30A extends. The direction of the striking end 30B is an axial direction X. The driving shaft 30 is connected to the driving shaft 121 of the motor 12, and the driving shaft 30 is provided with three power transmission slots 31, and each of the power transmission slots 31 respectively A planetary gear 23 is received, and the transmission shaft 121 passes through the transmission end 30A of the driving shaft 30 and meshes with each of the planetary gears 23, thereby driving the planetary gears 23 to rotate, so that the driving shaft 30 can be along In the circumferential direction, the driving shaft 30 is provided with at least two symmetrically arranged sliding grooves 32 and at least two symmetrically arranged connecting grooves 33. Each of the sliding grooves 32 has a first end 321 and a second end 322, respectively. The first end 321 is relatively close to the second end 322 of the transmission end 30A. In the embodiment, the connecting groove 33 extends in a direction parallel to the axial direction X, and the two ends of the connecting groove 33 are respectively connected to the one end. a first end 321 of the sliding groove 32 and a second end 322 of the other sliding groove 32, Each of the sliding grooves 32 and the connecting grooves 33 are alternately connected and surround the driving shaft 30. In the embodiment, the number of the sliding grooves 32 and the connecting grooves 33 is three, and the driving shaft 30 has a surrounding The positioning shaft 34 of the driving shaft 30 is spaced apart from each of the sliding grooves 32 by a disengagement space 35, and the driving shaft 30 is provided with a matching hole.

a hammering member 40 is sleeved on the driving shaft 30, and the driving shaft 30 is rotatable in the circumferential direction in the hammering member 40. The hammering member 40 is provided with at least two symmetrically arranged through holes. 41. Each of the through holes 41 is respectively provided with a sliding bead 42. The end of the hammering member 40 away from the motor 12 has a striking portion 43 having a first abutting surface 431 facing the motor 12. In the embodiment, the number of the at least two symmetrically arranged through holes 41 and the at least two symmetrically arranged sliding beads 42 is three, so that the hammering member 40 can be balancedly sleeved on the driving shaft 30. And the outer peripheral surface of the hammer member 40 has three symmetrically arranged first restriction surfaces 44.

A fixing ring member 50 is sleeved on the hammering member 40, so that the hammer member 40 is fixed in the fixing ring member 50 and cannot rotate along the circumferential direction of the driving shaft 30, and the fixing ring member 50 is inside. A plurality of the sliding beads 42 are disposed in the respective through holes 41 and abut against the sliding grooves 32 of the driving shaft 30 , and the fixing ring member 50 is adjacent to the motor 12 . One end has a fixing portion 51, and the fixing portion 51 has a second abutting surface 511 facing the first abutting surface 431, and the fixing portion 51 further has a plurality of lugs 512; in this embodiment, the fixing portion 51 The inner circumferential surface of the fixing ring member 50 has three symmetrically arranged second limiting surfaces 52, and the second limiting surface 52 is provided to abut against the first limiting surface 44 so that the hammering member 40 cannot follow the circumferential direction. Rotate.

An elastic member 60 is a spring in the embodiment, and one end of the elastic member 60 abuts against the first abutting surface 431, and the other end of the elastic member 60 abuts against the second abutting surface 511. The elastic member 60 is disposed between the hammer member 40 and the fixing ring member 50, so that the hammer member 40 is pushed in the direction of the fixing ring member 50 along the axial direction X, so that the sliding member 40 The beads 42 respectively abut against each of the sliding grooves 32;

A tool head 70 has a connecting portion 71 and a working portion 72. The connecting portion 71 is connected to the driving shaft 30 and is a polyhedron 70'. The polyhedron 70' is inserted into a matching hole fixed to the driving shaft 30. The working section 72 is provided with a connecting working head, and the connecting section 71 and the working section 72 have a pushing ring wall 73 which abuts against the hammering member 40.

A fixed front case 80 is fixedly coupled to the body 10 and is configured to pass the tool head 70. The fixing ring member 50 is disposed in the fixed front case 80, and the fixed front case 80 is sleeved on the fixing ring. The fixed front housing 80 is provided with a plurality of displacement holes 81 along the axial direction X, and the fixed front housing 80 is further provided with three fastening holes 82 opposite to the other ends of the displacement holes 81. The button holes 82 are provided for fixedly engaging the respective lugs 512 such that the fixing ring member 50 cannot rotate in the circumferential direction.

A change group 90 has a change ring member 91. The change ring member 91 is sleeved on the fixed front case 80, and the change ring member 91 has at least two push pins 911, and each of the push pins 911 can respectively Sliding along the axial direction X is inserted into each of the displacement holes 81, and the shifting ring member 91 is displaced along the axial direction X, so that each of the pushing feet 911 passes through the displacement holes 81 along The axial direction X is pushed against the hammering member 40, and the hammering member 40 is displaced along the axial direction X toward the fixing ring member 50, and the sliding ball 42 located in each of the through holes 41 is along the axial direction. X moves to the detachment space 35;

Preferably, the change group 90 further has a rotating ring 92 sleeved on the fixed front case 80. The rotating ring 92 has a ring inner surface 921 facing each of the displacement holes 81, and the ring inner surface 921 has A plurality of trapezoidal slopes 922 are disposed along a circumferential surface of the rotating ring 92, and each of the trapezoidal slopes 922 has a lower end connecting the inner surface 921 of the ring and a top end away from the inner surface 921 of the ring, and the conversion ring member 91 There is a plurality of extending ears 912, each of the extending ears 912 abutting against each of the trapezoidal slopes 922, and the pushing ring 911 of the changing ring member 91 is inserted into each of the displacement holes 81, so that the changing ring member is 91 is unable to rotate in the circumferential direction, and by rotating the rotating ring 92, the different heights of the trapezoidal slopes 922 correspond to the respective extending ears 912 of the rotating ring 92, thereby causing the changing ring member 91 to follow the axis Moving toward X toward the motor 12, each of the pushing feet 911 pushes against the striking portion 43 of the hammering member 40, causing the hammering member 40 to move toward the motor 12 along the axial direction X, and the hammering member 40 Each of the balls 42 is moved along the axial direction X to the detachment space 35.

Preferably, the number of the through holes 41 and the sliding beads 42 is not limited to three, and the number of the through holes 41 and the sliding beads 42 can be four, five, six, etc., and the number thereof is not limited, and plural numbers are used. The through holes 41 are circumferentially arranged on the hammering member 40, so that the through holes 41 are arranged symmetrically, and the number of the sliding beads 42 corresponds to the number of the through holes 41, and is respectively installed in each of the through holes 41. The number of the sliding grooves 32 of the driving shaft 30 also corresponds to the number of the through holes 41, and each of the sliding grooves 32 is symmetrically arranged around the driving shaft 30 so that each of the through holes 41 The balls 42 can be correspondingly placed in the respective sliding grooves 32.

The above is the structural configuration of the present invention and its connection relationship, and the usage method of the present invention is as follows:

Referring to FIG. 2 to FIG. 4, the motor 12 rotates and drives the driving shaft 30 to rotate. When the driving shaft 30 rotates, the sliding beads 42 in the sliding grooves 32 are abutted. Moving along each of the sliding grooves 32, the hammers 40 are displaced by the respective sliding balls 42 along the axial direction X. When the sliding balls 42 are located at the second end 322, the hammering members 40 are along The axial axis X is displaced away from the motor 12, and the elastic member 60 abuts against the hammer member 40, so that the sliding ball 42 of the hammering member 40 abuts against the sliding groove 32; when the driving shaft 30 rotates, the When the sliding bead 42 is located at the first end 321 , the hammering member 40 is restrained by each of the sliding beads 42 , so that the hammering member 40 is displaced along the axial direction X to approach the motor 12 and compress the elastic member 60 . When the driving shaft 30 rotates to move the sliding ball 42 to the second end 322 of the sliding groove 32 through the connecting groove 33, the elastic member 60 pushes against the hammering member 40 to make the hammer The piece 40 is rapidly moved away from the motor 12 along the axial direction X, thereby causing the hammering member 40 to drive the tool head 70 to produce simultaneous rotation and hammering.

Referring to FIG. 2 and FIG. 4 , when each of the sliding beads 42 of the hammering member 40 is located at the second end 322 of the driving shaft 30 , the hammering member 40 is located farthest from the motor 12 , and the The elastic member 60 is in a relaxed state;

Referring to FIG. 3 and FIG. 4, when the driving shaft 30 rotates, the position of the sliding groove 32 corresponding to each of the sliding balls 42 is moved from the second end 322 to the first end 321 , and during the moving process, the hammer is moved. The punching member 40 is pinned by each of the sliding beads 42 such that the hammering member 40 approaches the motor 12 along the axial direction X, thereby causing the striking portion 43 of the hammering member 40 to compress the elastic member 60 as the driving shaft. 30 continues to rotate, so that the position of the sliding groove 32 corresponding to each of the sliding beads 42 is moved from the first end 321 to each of the connecting grooves 33, since the two ends of the connecting groove 33 are connected to the first end 321 of one of the sliding grooves 32. And the second end 322 of the other sliding groove 32, so that the connecting groove 33 becomes the relationship between the first end 321 and the second end 322 of the two different sliding grooves 32, so the connecting groove of the driving shaft 30 When the position corresponding to the slide ball 42 is located, the hammer member 40 is pushed against the elastic member 60, and is quickly moved away from the motor 12 from a position close to the motor 12, so that the tool head 70 completes simultaneous rotation and hammering. .

More preferably, the present invention can also stop the hammering operation. Referring to FIG. 7, the user can rotate the rotating ring 92 so that the top end of the trapezoidal slope 922 on the rotating ring 92 is located at the extended ear corresponding to the changing ring member 91. The position of the 912 is such that the change ring member 91 is displaced along the axial direction X toward the motor 12, so that each of the pushing feet 911 of the change ring member 91 passes through each of the displacement holes 81 and pushes against the hammer member. 40, the hammering member 40 is moved along the axial direction X toward the motor 12, and the hammering member 40 drives each of the sliding beads 42 to move along the axial direction X toward the motor 12, and moves to the corresponding position. Deviating from the position of the space 35, at this time, even if the driving shaft 30 rotates, since each of the sliding beads 42 of the hammering member 40 has been separated from each of the sliding grooves 32, the hammering member 40 does not follow each of the sliding grooves. 32 and X displacement along the axial direction, thereby making the invention only rotational.

Finally, referring to FIG. 8, in another embodiment, the hammer drill can only have a hammering action, and the connecting portion 71 of the tool head 70 is a cylinder, thereby making the tool head 70 unable to cooperate with the active tool head 70. The shaft 30 moves in the same direction, so that the tool head 70 can only be hammered by the hammer member 40.

Therefore, the present invention achieves the hammering action by the sliding groove 32 provided on the driving shaft 30, the sliding ball 42 of the hammering member 40, the fixing ring member 50 and the elastic member 60, and the driving shaft 30 can At the same time, the tool head 70 is rotated, so that the invention can be converted into a linear reciprocating motion only by the rotary motion, and the hammer drill can complete the hammering action and the circumferential rotation motion along the axial direction X.

10‧‧‧ Ontology

11‧‧‧Shell

111‧‧‧ accommodating space

12‧‧‧ motor

121‧‧‧ drive shaft

20‧‧‧ planetary gear set

21‧‧‧Fixed parts

211‧‧‧ buckle groove

22‧‧‧ ring gear

221‧‧‧Fixed ribs

23‧‧‧ planetary gear

30‧‧‧Drive shaft

30A‧‧‧Drive end

30B‧‧‧Beat end

31‧‧‧Power transmission slot

32‧‧‧ slip groove

321‧‧‧ first end

322‧‧‧ second end

33‧‧‧ Connection trench

34‧‧‧Location垣

35‧‧‧Without space

40‧‧‧ Hammering pieces

41‧‧‧through holes

42‧‧‧Slide beads

43‧‧‧Beat Department

431‧‧‧First topping

44‧‧‧First limit surface

50‧‧‧Fixed ring

51‧‧‧ Fixed Department

511‧‧‧Second topping

512‧‧‧ 扣耳

52‧‧‧second limit surface

60‧‧‧Flexible parts

70‧‧‧Tool head

70’‧‧‧ Polyhedron

71‧‧‧ Connection section

72‧‧‧Working section

73‧‧‧ pushed to the wall

80‧‧‧Fixed front shell

81‧‧‧ displacement hole

82‧‧‧ buttonhole

90‧‧‧Transformation group

91‧‧‧Transform ring

911 ‧ ‧ push the foot

912‧‧‧ Extended ear

92‧‧‧Rotating ring

921‧‧‧ inside the ring

922‧‧‧Trapezoidal slope

X‧‧‧ axial

1 is an exploded view of the present invention in a preferred embodiment. 2 is a cross-sectional view showing the position of the sliding bead at the second end corresponding to the sliding groove after assembly according to the present invention. Figure 3 is a cross-sectional view showing the position of the sliding bead at the first end corresponding to the sliding groove after assembly according to the present invention. 4 is a side view of the drive shaft of the present invention and a positional state of the slide ball. Figure 5 is a perspective view of the rotating ring of the present invention. Figure 6 is a perspective view of the fixed front case of the present invention. Figure 7 is a cross-sectional view of the hammer member after the rotating ring is rotated by the shifting ring member of the present invention. Figure 8 is an exploded view of another preferred embodiment of the present invention.

Claims (7)

A hammer drill comprising: a body having a motor; a drive shaft having an opposite drive end and a strike end, the drive end extending to the strike end in an axial direction, the drive end being provided with a mating hole The driving shaft is coupled to the motor to enable the driving shaft to rotate along a circumferential direction. The driving shaft is provided with at least two symmetrically arranged sliding grooves and at least two symmetrically arranged connecting grooves, each of the sliding grooves respectively having a first end and a second end, the first end is closer to the driving end than the second end, and the two ends of each connecting groove are respectively connected to one of the first end of the sliding groove and the other sliding groove The second end of the sliding groove and each of the connecting grooves are alternately connected and surround the driving shaft; a hammering member is sleeved on the driving shaft, and the hammering member is provided with at least two symmetrically arranged a sliding bead is disposed in each of the through holes; a fixing ring member is fixedly sleeved on the hammering member, and an inner wall surface of the fixing ring member abuts against each of the sliding beads, so that each sliding bead is limited Each of the sliding grooves located in each of the through holes and abutting against the driving shaft; a member disposed between the hammering member and the fixing ring member, the hammering member is pushed along the axial direction in a direction opposite to the fixing ring member, and each of the sliding beads is respectively abutted against each of the sliding members And a tool head having a connecting section and a working section, the connecting section being a polyhedron and connecting the engaging hole of the driving shaft, wherein the working section is configured to connect the working head, the connecting section and the working section There is a push against the ring wall, and the push ring wall abuts against the hammer. The hammer drill of claim 1, wherein the driving shaft has a positioning ridge around the driving shaft, the positioning 垣 has a detachment space from each of the sliding grooves, and has a fixed front shell and a transformation. The fixed front shell is sleeved on the fixing ring member, and the fixed front shell is provided with at least two displacement holes, the conversion group has a conversion ring member, and the conversion ring member is sleeved on the fixed front shell And the at least two pushing feet are disposed on the shifting ring, and each of the pushing legs is slidably inserted into each of the displacement holes, and the shifting ring member is displaced along the axial direction to make each Pushing the foot through each of the displacement holes to push the hammering member along the axial direction, thereby causing the hammering member to be displaced along the axial direction toward the fixing ring member, and limiting the sliding bead along each of the through holes The axial movement is moved to the detachment space. The hammer drill of claim 2, wherein the conversion set further has a rotating ring sleeved on the fixed front case, the rotating ring has a ring inner surface facing each of the displacement holes, and the inner surface of the ring Having two trapezoidal slopes along a circumferential surface of the rotating ring, and each of the trapezoidal slopes has a lower end connecting the inner surface of the ring and a top end away from the inner surface of the ring, and the conversion ring has two extending ears. The two extending ears respectively abut against the two trapezoidal slopes, and the pushing ring of the changing ring member is placed in each of the displacement holes, so that the changing ring member cannot rotate in the circumferential direction, and the rotation is rotated by Ring, the different heights of the two trapezoidal slopes correspond to the two extended ears of the rotating ring, and the moving ring member is moved toward the motor along the axial direction, and each of the pushing feet pushes against the hammering member And moving the hammering member toward the motor along the axial direction, and the hammering member drives each of the sliding balls to move along the axial direction to the disengagement space. The hammer drill of claim 1, wherein the motor has a transmission shaft that is rotatable in a circumferential direction, the transmission shaft is provided with an external tooth, and a planetary gear set is disposed in the body. The planetary gear set has a fixing member, a ring gear and three planetary gears. The fixing member is fixedly mounted in the body and is provided for the transmission shaft to pass therethrough, and the fixing member has a plurality of buckle grooves, the ring gear Fixed in the fixing member, and each of the planetary gears is engaged in the ring gear, and the driving shaft is provided with three power transmission slots, each of the power transmission slots respectively accommodating one of the planetary gears, and the transmission shaft passes through The driving end of the driving shaft meshes with each of the planetary gears, thereby driving each of the planetary gears to rotate, so that the driving shaft can rotate in the circumferential direction. The hammer drill of claim 1, wherein the outer peripheral surface of the hammering member has a first limiting surface, and the inner peripheral surface of the fixing ring has a second limiting surface, the second limiting surface is provided with abutting The first limiting surface further causes the hammer to rotate along the circumferential direction. The hammer drill of claim 1, wherein the hammering member has a striking portion at an end away from the motor, the striking portion having a first abutting surface facing the motor, the fixing ring member being adjacent to one end of the motor The fixing portion has a second abutting surface facing the first abutting surface, and one end of the elastic member abuts against the first abutting surface, and the other end of the elastic member abuts against the Second to the top. The hammer drill of claim 1, wherein the connecting section of the tool head is a cylinder.