Driving tools

Abstract

To provide a hammering tool in which a driver is moved using gas pressure to hammer a hammering tool, and returns the driver to a standby position above a downward motion end by engaging with a wheel of a lift mechanism, and a rotary shaft for supporting the wheel is supported by a shaft bearing, and further, in which the lift mechanism can be made compact in an axial direction by devising an arrangement of the shaft bearing.SOLUTION: A rotary shaft 21 is connected by splines to a carrier 43c of a planetary gear mechanism 43 of a last stage. A shaft bearing 48 supporting the rotary shaft 21 is arranged on an outer peripheral side of the carrier 43c. The shaft bearing 48 and the carrier 43c are overlapped and arranged in a motor axis J direction, and thereby a lift mechanism 20 can be made compact.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a driving tool for driving a driving tool such as a nail or staple into wood or the like. [Background technology]

[0002] Patent Document 1 discloses a gas spring type driving tool that uses the thrust of compressed gas as a striking force. The gas spring type driving tool has a piston that moves up and down within a cylinder, and a driver that is connected to the piston and moves downward as a unit to strike the driving tool. The piston and driver move downward in the driving direction due to the gas pressure in the pressure accumulator. The piston and driver are returned in the opposite direction to the driving direction by a lift mechanism.

[0003] The lift mechanism has a wheel with multiple engaging portions that engage with engaged portions provided on the driver. The wheel is rotated by an electric motor. After a driving operation, the wheel rotates and the engaging portions sequentially mesh with the engaged portions of the driver, moving the driver upward in the direction opposite to the driving operation. As the piston moves upward in the direction opposite to the driving operation, the gas pressure in the accumulator chamber increases. As the lift mechanism disengages from the driver that has been moved upward to its uppermost position, the driver is moved downward by the gas pressure, performing a striking operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 10,946,506 Summary of the Invention [Problem to be solved by the invention]

[0005] In the lift mechanism disclosed in Patent Document 1, a wheel is rotatably supported by a rotating shaft. The output of an electric motor is transmitted to the rotating shaft via a reduction gear unit. The rotating shaft is rotatably supported on a mechanism case via two bearings. Of the two bearings, the lower bearing in particular is positioned between the wheel and the reduction gear unit, making it difficult to make the lift mechanism compact in the motor axial direction. This disclosure aims to make the lift mechanism compact in the motor axial direction. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a driving tool includes a piston that moves in the driving direction, for example, by gas pressure, a driver that moves integrally with the piston to strike the driving tool, and a lift mechanism that moves the driver in the direction opposite to the driving direction. The lift mechanism includes, for example, an electric motor, a planetary gear mechanism that reduces the output of the electric motor, and a rotating shaft that is coupled to the carrier of the planetary gear mechanism and rotated by the electric motor. The lift mechanism includes, for example, a bearing that rotatably supports the rotating shaft on the outer periphery of the carrier, and a wheel that is supported on the rotating shaft and engages with the driver. This allows the lift mechanism to be made more compact in the motor axial direction. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. [Figure 2] 2 is a cross-sectional view taken along line II-II in FIG. 1, showing a longitudinal cross-sectional view of the tool main body. [Figure 3] 3 is a cross-sectional view taken along the line III-III in FIG. 1, showing a cross-sectional view of the lift mechanism. [Figure 4] FIG. 4 is an enlarged view of part IV in FIG. 3, showing the lift mechanism and the speed reducer. [Figure 5] FIG. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 4, showing a cross-sectional view of the first stage planetary gear mechanism. [Figure 7]FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 4, showing a cross-sectional view of the second stage planetary gear mechanism. [Figure 8] 8 is a cross-sectional view taken along line VIII-VIII in FIG. 4, showing a transverse cross-sectional view of the final-stage planetary gear mechanism. [Figure 9] 9 is a cross-sectional view of the spline coupling portion taken along line IX-IX in FIG. 4. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] In one or more embodiments, the rotating shaft, carrier, and bearings are arranged on the same plane perpendicular to the motor axis of the electric motor, for example, so that the rotating shaft, carrier, and bearings are arranged compactly in the motor axial direction.

[0009] In one or more embodiments, for example, multiple planetary gear mechanisms are arranged in series. For example, the internal gear of the final planetary gear mechanism is supported by a metal mechanism case that houses a wheel. This provides a strong support for the internal gear of the final planetary gear mechanism.

[0010] In one or more embodiments, for example, the rotating shaft and the carrier are connected by a spline engagement, which allows the rotational output of the electric motor to be efficiently transmitted to the rotating shaft.

[0011] In one or more embodiments, for example, the splined engagement is a large diameter splined engagement, which allows the rotational output of the electric motor to be transmitted to the rotating shaft more efficiently.

[0012] In one or more embodiments, for example, multiple planetary gear mechanisms are arranged in series. For example, the upstream planetary gear mechanisms, excluding the final planetary gear mechanism, are housed in a plastic gear case. This reduces the weight of the lift mechanism.

[0013] In one or more embodiments, for example, planetary gear mechanisms are arranged in series in multiple stages. For example, the displacement of the internal gear of the final-stage planetary gear mechanism in the motor axial direction is restricted by the outer ring of the bearing. This simplifies the configuration.

[0014] In one or more embodiments, a contact portion is provided on a side surface of the internal gear, protruding in the axial direction of the motor, to contact a side surface of the outer ring, thereby ensuring an appropriate clearance between the internal gear and the bearing and preventing interference of the planetary gear with the bearing. [Example]

[0015] FIG. 1 shows, as an example of a driving tool 1, a gas spring type driving tool that uses the gas pressure in the upper chamber of a cylinder as a thrust for driving a driving tool N. In the following explanation, as shown in each figure, the driving direction of the driving tool N is defined as downward, and the opposite driving direction is defined as upward. A driver 15, which will be described below, moves downward to drive the driving tool N, and after driving, the driver 15 is returned upward. A user of the driving tool 1 is positioned generally on the left side of the driving tool 1 in FIG. 1. The side in front of the user is defined as the rear side (user side), and the front is defined as the front side. Furthermore, left and right directions are based on the user.

[0016] As shown in Figures 1 and 2, the driving tool 1 has a main body 10. The main body 10 has a configuration in which a cylinder 12 is housed inside a generally cylindrical main body housing 11. A piston 13 is housed inside the cylinder 12 so that it can reciprocate up and down. The upper part of the cylinder 12 is connected to a pressure accumulator chamber 14. Gas pressure in the pressure accumulator chamber 14 acts on the upper surface of the piston 13 as a thrust for striking.

[0017] A long driver 15 is connected to the underside of the piston 13. The driver 15 extends downward. The lower side of the driver 15 enters the driving passage 2a of the driving nose 2, which is provided on the underside of the main body 10. The gas pressure in the pressure accumulator 14 acting on the upper surface of the piston 13 causes the driver 15 to move downward within the driving passage 2a, striking a single driving tool N. Figure 2 shows a state in which a single driving tool N has been supplied to the driving passage 2a. The driving tool N struck by the driver 15 is ejected from the ejection port 2b of the driving nose 2. The ejected driving tool N is driven into the workpiece W. Figure 1 shows a state in which the driving tool N has been driven into the workpiece W. A lower-end damper 16 is located at the bottom of the cylinder 12 to absorb impact at the lower end of the piston 13.

[0018] A contact arm 2c is provided around the injection port 2b at the bottom of the driving nose 2 so that it can be displaced up and down. The arm portion of the contact arm 2c extends upward and reaches the vicinity of the switch lever 3a. When the driving tool 1 is pressed down with the contact arm 2c in contact with the driving portion of the workpiece W, the contact arm 2c is moved upward relative to the driving nose 2. The upward movement of the contact arm 2c is one of the conditions for starting the driving operation. This prevents inadvertent driving operations.

[0019] A grip section 3 that is held by the user is provided on the side of the main body section 10. A switch lever 3a that is pulled by the user with the fingertip is provided on the underside of the front of the grip section 3. A battery attachment section 4 is provided on the rear of the grip section 3. A battery pack 5 is attached to the battery attachment section 4. The drive section 30, which will be described later, operates using the power of the battery pack 5 as its power source. A hook 7 for hanging is provided on the side of the battery attachment section 4.

[0020] A magazine 6 is connected to the lower side of the driving nose 2. A large number of driving tools N loaded in the magazine 6 are supplied one by one into the driving passage 2a in conjunction with the driving operation.

[0021] A lift mechanism 20 is connected to the upper side of the driving nose 2. The lift mechanism 20 has the function of moving the piston 13 and the driver 15 upward together after striking. When the lift mechanism 20 moves the piston 13 upward, the gas pressure in the pressure accumulator chamber 14 is increased.

[0022] As shown in FIG. 3, the lift mechanism 20 has a drive unit 30 and a reduction gear unit 40 arranged in series in the front-rear direction. The drive unit 30 and the reduction gear unit 40 operate the lift mechanism 20. The drive unit 30 has an electric motor 32. The electric motor 32 is housed in a drive unit case 31 that straddles the lift mechanism 20 and the lower part of the battery attachment unit 4 in a generally L-shaped configuration. The drive unit case 31 is integrally formed with the main body housing 11. The main body housing 11 and the drive unit case 31 have a left-right half structure. FIGS. 3, 6 to 8 show that the drive unit case 31 has a half structure in which a right half case 31R and a left half case 31L are butt-joined to each other with multiple screws 31d. The drive unit case 31 extends forward. The reduction gear unit 40 and the lift mechanism 20 are housed in the front side of the drive unit case 31.

[0023] The electric motor 32 is housed with the axis of the motor shaft 33 (motor axis J) oriented along the front-to-rear direction perpendicular to the driving direction (the direction perpendicular to the plane of the paper in FIG. 3). The electric motor 32 is powered by the power of the battery pack 5. As described above, the electric motor 32 is started by pulling the switch lever 3a.

[0024] A motor shaft 33 of the electric motor 32 is rotatably supported by the drive unit case 31 via bearings 34 and 35. The front bearing 34 is held by a front partition wall 31a of the drive unit case 31. The rear bearing 35 is held by a rear partition wall 31b of the drive unit case 31. Between the front and rear partition walls 31a and 31b, the drive unit case 31 functions as a motor case.

[0025] A cooling fan 36 and a drive gear 37 are connected to the front of the motor shaft 33. The front side of the motor shaft 33 is supported by a bearing 34 via the drive gear 37. The drive gear 37 protrudes forward from the front partition wall 31a. The drive gear 37 protruding forward is connected to a reduction gear unit 40.

[0026] Details of the reduction gear unit 40 are shown in Figure 4. The reduction gear unit 40 has three-stage planetary gear mechanisms 41, 42, and 43. The three-stage planetary gear mechanisms 41, 42, and 43 are housed in a resin gear case 45. A rear portion 45a of the gear case 45 is cylindrical. The cylindrical rear portion 45a is sandwiched and coupled between the outer periphery of the bearing 34 and the retaining hole 31c of the partition wall portion 31a. The gear case 45 is covered by the drive unit case 31.

[0027] The three-stage planetary gear mechanisms 41, 42, and 43 are arranged coaxially (in series) on the motor axis J. As shown in FIGS. 4, 5, and 6, the first-stage planetary gear mechanism 41 on the upstream (rear) side has three planetary gears 41a, one carrier 41b, and one internal gear 41c. The three planetary gears 41a are meshed with the drive gear 37. The drive gear 37 corresponds to the sun gear of the first-stage planetary gear mechanism 41. As shown in FIG. 4, the internal gear 41c is fixed along the inner surface of the gear case 45. The three planetary gears 41a are meshed with the internal gear 41c. The three planetary gears 41a are rotatably supported by one carrier 41b via a support shaft 41d.

[0028] The sun gear 42a of the second-stage planetary gear mechanism 42 is integrally formed on the front surface of the carrier 41b of the first-stage planetary gear mechanism 41. As shown in FIGS. 4, 5, and 7, three planetary gears 42b mesh with the sun gear 42a. The three planetary gears 42b are rotatably supported by one carrier 42c via support shafts 42e. The three planetary gears 42b mesh with one internal gear 42d. As shown in FIG. 4, the internal gear 42d is fixed along the inner surface of the gear case 45. An annular intermediate member 46 is sandwiched between the internal gear 42d of the second-stage planetary gear mechanism 42 and the internal gear 41c of the first-stage planetary gear mechanism 41. This restricts displacement of the internal gears 41c, 42d in the direction of the motor axis J.

[0029] The sun gear 43a of the third-stage planetary gear mechanism 43 is integrally formed on the front surface of the carrier 42c of the second-stage planetary gear mechanism 42. As shown in Figures 4, 5, and 8, five planetary gears 43b mesh with the sun gear 43a. The five planetary gears 43b are rotatably supported by one carrier 43c via support shafts 43e. The five planetary gears 43b mesh with one internal gear 43d.

[0030] 4, the internal gear 43d of the third-stage planetary gear mechanism 43 is fixed along the inner periphery of the mechanism case 25 of the lift mechanism 20. An annular interposition member 47 is sandwiched between the internal gear 43d of the third-stage planetary gear mechanism 43 and the internal gear 42d of the second-stage planetary gear mechanism 42. This restricts displacement of the internal gears 42d, 43d in the direction of the motor axis J.

[0031] As shown in Figures 4 and 9, the carrier 43c of the third-stage planetary gear mechanism 43 is rotatably supported by the mechanism case 25 via a bearing 48. Therefore, the third-stage planetary gear mechanism 43 is supported by the mechanism case 25. The mechanism case 25 is made of an aluminum alloy and has a cylindrical shape. As shown in Figures 3 and 4, the rear side of the mechanism case 25 extends into the front inner peripheral side of the gear case 45. As a result, the mechanism case 25 and the gear case 45 are joined coaxially with the motor axis J.

[0032] 4, 5, and 9, in this embodiment, the bearing 48 is a ball bearing with a large number of steel balls 48c sandwiched between an inner ring 48a and an outer ring 48b. The outer ring 48b of the bearing 48 abuts against the internal gear 43d of the third-stage planetary gear mechanism 43. Five abutment portions 43f are provided on the front surface of the internal gear 43d so as to protrude forward one step higher. The five abutment portions 43f are arranged at five equal intervals in the circumferential direction. The outer ring 48b abuts against the front surfaces of the abutment portions 43f. This prevents interference between the bearing 48 and the five planetary gears 43b that revolve around the motor axis J.

[0033] The rotating shaft 21 of the lift mechanism 20 is coupled to the carrier 43c of the third-stage planetary gear mechanism 43. The splined shaft portion 21a at the rear of the rotating shaft 21 is engaged with the splined hole 43g of the carrier 43c. The splined engagement integrates the rotating shaft 21 with the carrier 43c for rotation around the motor axis J. In this embodiment, the splined shaft portion 21a of the rotating shaft 21 is splined to the splined hole 43g of the carrier 43c by large diameter engagement (old JIS standard D2001). Therefore, as shown in FIG. 9, the large diameter surface (the outer peripheral surface of the teeth) of the splined shaft portion 21a abuts against the bottom surface of the splined hole 43g. The rotational output of the electric motor 32 is output to the rotating shaft 21 of the lift mechanism 20 via the splined engagement of the carrier 43c. The third-stage planetary gear mechanism 43 corresponds to the final-stage planetary gear mechanism of the reduction gear unit 40.

[0034] 3 and 4, the lift mechanism 20 has a rotary shaft 21 connected to the reduction gear unit 40 and a wheel 22 supported by the rotary shaft 21. The rear side of the rotary shaft 21 is connected to the carrier 43c by spline engagement. The carrier 43c is rotatably supported on the mechanism case 25 via the bearing 48. The bearing 48 is held on the outer periphery of the carrier 43c of the third-stage planetary gear mechanism 43. Therefore, the bearing 48 is arranged to overlap the carrier 43c in the direction of the motor axis J. As a result, the bearing 48, the carrier 43c, and the rear part of the rotary shaft 21 are arranged side by side on the same plane perpendicular to the motor axis J.

[0035] This arrangement of the bearing 48 contributes to a more compact lift mechanism 20. For example, in the case of a conventional configuration in which the rear portion of the rotary shaft 21 is directly inserted into the inner ring 48a of the bearing 48 and held therein, the carrier 43c and the bearing 48 are arranged side by side in the direction of the motor axis J (arranged without overlapping), which requires additional space in the direction of the motor axis J.

[0036] The front side of the rotating shaft 21 is rotatably supported by a mechanism case 25 via a bearing 23. The front part of the mechanism case 25 is closed by a lid part 24. The front bearing 23 is held by the lid part 24. The rotation axis of the rotating shaft 21 coincides with the motor axis J.

[0037] When the electric motor 32 is started, the wheel 22 of the lift mechanism 20 rotates integrally. The wheel 22 rotates counterclockwise as indicated by the arrow R in FIG. 2. As shown in FIGS. 2, 3, and 4, the wheel 22 has two flange portions 22a that are parallel to each other and spaced apart by a fixed distance. A plurality of engagement portions 22b are provided across the peripheries of the two flange portions 22a, supported at both ends. Each engagement portion 22b uses a cylindrical shaft member (pin).

[0038] The left part of the wheel 22 is inserted into the driving passage 2a. Within the driving passage 2a, each engaging portion 22b of the wheel 22 engages with an engaged portion 15a of the driver 15. A plurality of engaged portions 15a are arranged at regular intervals in the longitudinal direction (vertical direction) of the driver 15. Each engaged portion 15a has a rack tooth shape and is provided so as to protrude laterally.

[0039] As shown in Figure 2, in a standby state in which the piston 13 and driver 15 are held in an upper standby position, the electric motor 32 is started by pulling the switch lever 3a. When the electric motor 32 is started, the wheel 22 rotates counterclockwise, disengaging the engaging portion 22b of the wheel 22 from the engaged portion 15a of the driver 15. This causes the piston 13 and driver 15 to move downward due to the gas pressure in the pressure accumulator chamber 14. As the driver 15 moves downward within the driving passage 2a, one driving tool N is struck and fired from the injection port 2b.

[0040] After injection, the electric motor 32 remains activated and the wheel 22 continues to rotate, causing the engaging portion 22b to again engage with the engaged portion 15a of the driver 15. As the wheel 22 rotates and the engaging portion 22b sequentially engages with the engaged portion 15a, the driver 15 and piston 13 are returned to their upper standby positions. For example, by appropriately controlling the time from the activation of the electric motor 32, the electric motor 32 is stopped when the driver 15 and piston 13 reach their standby positions. This completes the series of driving operations.

[0041] The wheel 22 is supported so as to be displaceable in the radial direction relative to the rotary shaft 21. The rotary shaft 21 is provided with two flat support surfaces 21b facing each other for supporting the wheel 22 so as to be displaceable in the radial direction. The support hole of the wheel 22 is provided with flat surfaces that are parallel to each other. The support surfaces 21b are in sliding contact with the flat surfaces of the support hole. This allows the wheel 22 to be supported so as to be displaceable in the radial direction within a certain range relative to the rotary shaft 21. As the wheel 22 displaces in the radial direction relative to the rotary shaft 21, abnormal reaction force from the engaged portion 15a against the engaging portion 22b is buffered, maintaining a normal meshing state between the two. The radial displacement of the wheel 22 is restored to its initial position by the compression spring 21c.

[0042] According to the driving tool 1 described above, the rear bearing 48 that supports the rotary shaft 21 is held on the outer circumferential side of the carrier 43c of the final-stage planetary gear mechanism 43. By arranging the bearing 48 on the outer circumferential side of the carrier 43c so as to overlap in the direction of the motor axis J, the lift mechanism 20 can be made more compact in the direction of the motor axis J.

[0043] According to this embodiment, the three components, namely, the spline shaft portion 21a of the rotating shaft 21, the carrier 43c, and the bearing 48, are arranged side by side on the same plane perpendicular to the motor axis J. This allows the rotating shaft 21, the carrier 43c, and the bearing 48 to be compactly arranged in the direction of the motor axis J.

[0044] According to this embodiment, the third stage (final stage) planetary gear mechanism 43 is supported by the metal mechanism case 25. This allows the final stage planetary gear mechanism 43 to be firmly supported against vibrations and shocks.

[0045] According to the embodiment, the rotating shaft 21 and the carrier 43c are coupled by a spline engagement, which allows the rotational output of the electric motor 32 to be efficiently transmitted to the rotating shaft 21. In particular, since the spline engagement is a large-diameter spline engagement, the rotational output of the electric motor 32 is transmitted to the rotating shaft 21 even more efficiently.

[0046] According to the embodiment, of the three-stage planetary gear mechanisms 41, 42, and 43 of the reduction gear unit 40, the first and second stage planetary gear mechanisms 41 and 42 on the upstream side, excluding the final stage planetary gear mechanism 43, are housed in a resin gear case 45. This reduces the weight of the reduction gear unit 40.

[0047] According to this embodiment, displacement of the internal gear 43d of the final-stage planetary gear mechanism 43 in the direction of the motor axis J is restricted by the outer ring 48b of the bearing 48. This simplifies the configuration compared to a configuration in which a separate restricting member is provided.

[0048] According to this embodiment, an abutment portion 43f is provided on the side surface of the internal gear 43d of the final-stage planetary gear mechanism 43, protruding one step higher. The outer ring 48b of the bearing 48 abuts against the abutment portion 43f. This ensures an appropriate clearance between the internal gear 43d and the bearing 48, preventing, for example, interference of the planetary gear 43b with the bearing 48.

[0049] Various modifications can be made to the embodiment described above. For example, although the reduction gear unit 40 having three-stage planetary gear mechanisms 41, 42, and 43 has been exemplified, the arrangement of the bearings 48 shown as examples can also be applied to reduction gear units having one-stage or two-stage planetary gear mechanisms, or four or more stages of planetary gear mechanisms.

[0050] Although the configuration in which the wheel 22 is coupled to the rotary shaft 21 so as to be displaceable in the radial direction has been exemplified, such a displacement-allowing structure may be omitted.

[0051] Although the configuration in which the bearing 48 is a ball bearing has been exemplified, the same can be applied to the case in which a roller bearing is used.

[0052] Although the configuration in which the rotating shaft 21 is coupled to the carrier 43c of the final-stage planetary gear mechanism 43 by a large-diameter spline engagement has been exemplified, this may be changed to a tooth-face spline engagement. Also, the rotating shaft may be coupled to the final-stage planetary gear mechanism by a coupling means other than spline engagement, such as press-fitting or screw coupling.

[0053] The driving tool 1 of the embodiment is an example of a driving tool according to one aspect of the present disclosure. The piston 13 of the embodiment is an example of a piston according to one aspect of the present disclosure. The driver 15 of the embodiment is an example of a driver according to one aspect of the present disclosure.

[0054] The lift mechanism 20 of the embodiment is an example of a lift mechanism according to an aspect of the present disclosure. The electric motor 32 of the embodiment is an example of an electric motor according to an aspect of the present disclosure. The planetary gear mechanisms 41, 42, and 43 of the embodiment are an example of a planetary gear mechanism according to an aspect of the present disclosure. The carrier 43c of the embodiment is an example of a carrier according to an aspect of the present disclosure.

[0055] The rotating shaft 21 of the embodiment is an example of a rotating shaft according to an aspect of the present disclosure. The bearing 48 of the embodiment is an example of a bearing according to an aspect of the present disclosure. The wheel 22 of the embodiment is an example of a wheel according to an aspect of the present disclosure. [Explanation of symbols]

[0056] 1...Driving tool N...Driver 2...Driving nose part 2a... firing passage, 2b... ejection port, 2c... contact arm 3...Grip section 3a...Switch lever 4. Battery mounting section 5. Battery pack 6...Magazine 7...Hook 10...Main body 11...Main body housing 12...Cylinder 13...Piston 14...Accumulation chamber 15...Driver 15a...Engaged part 16...Lower moving end damper 20...Lift mechanism 21...Rotation axis 21a...spline shaft portion, 21b...support surface 22...Wheels 22a... flange portion, 22b... engagement portion 23...Bearing (front side) 24…Lid part 25...Mechanism case 30...Drive unit 31...Drive unit case 31R...Right half split case, 31L...Left half split case 31a...Partition wall portion (front side), 31b...Partition wall portion (rear side), 31c...Retaining hole, 31d...Screw 32...Electric motor J: Motor axis 33...Motor shaft 34, 35...Bearings 36...Cooling fan 37...Drive gear 40...Reduction gear section 41...First stage planetary gear mechanism 41a... planetary gear, 41b... carrier, 41c... internal gear, 41d... support shaft 42...Second stage planetary gear mechanism 42a...Sun gear, 42b...Planet gear, 42c...Carrier, 42d...Internal gear 43...Third stage planetary gear mechanism 43a...Sun gear, 43b...Planet gear, 43c...Carrier, 43d...Internal gear 43e...support shaft, 43f...contact portion, 43g...spline hole 45…Gear case 45a...rear 46, 47...Interposition member 48...Bearing (ball bearing) 48a...inner ring, 48b...outer ring, 48c...steel ball

Claims

1. A driving tool, A piston that moves in the driving direction by gas pressure, a driver that moves integrally with the piston and strikes the driving tool; a lift mechanism that moves the driver in a direction opposite to the driving direction; The lift mechanism includes: An electric motor; a planetary gear mechanism that reduces the output of the electric motor; a rotating shaft coupled to a carrier of the planetary gear mechanism and rotated by the electric motor; a bearing that rotatably supports the rotary shaft on an outer circumferential side of the carrier; a wheel supported on the axle and engaging the driver; a metal mechanism case that houses the wheel; A driving tool in which the planetary gear mechanism is arranged in series in multiple stages, and the internal gear of the final stage of the multiple stages of the planetary gear mechanism and the bearing are supported in direct contact with the mechanism case.

2. The driving tool according to claim 1, A driving tool in which the rotating shaft, the carrier, and the bearing are arranged on the same plane perpendicular to the motor axis of the electric motor.

3. The driving tool according to claim 1 or 2, A driving tool in which the rotating shaft and the carrier are connected by a spline engagement.

4. The driving tool according to claim 3, A driving tool, wherein the spline fitting is a large diameter fitting spline fitting.

5. The driving tool according to any one of claims 1 to 4, A driving tool in which the upstream planetary gear mechanism excluding the final stage planetary gear mechanism is housed in a gear case made of resin.

6. The driving tool according to any one of claims 1 to 5, A driving tool in which displacement of the internal gear of the final stage planetary gear mechanism in the motor axial direction is restricted by the outer ring of the bearing.

7. The driving tool according to claim 6, A driving tool having a contact portion protruding in the motor axial direction on a side surface of the internal gear for contact with a side surface of the outer ring.

8. A driving tool according to any one of claims 1 to 7, A driving tool in which the outer ring of the bearing is located on the inner peripheral side relative to the outer periphery of the internal gear.

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