Power tool

Abstract

To provide a technique which suppresses abrasion wear of components of a power tool.SOLUTION: A power tool includes: a rotary shaft which is rotated by a motor; and a housing which accommodates the rotary shaft. The rotary shaft includes: a first end part which is arranged in a first direction side of the axial direction of the rotary shaft; and a second end part which is arranged in a second direction side. The housing accommodates the rotary shaft, and can store lubricant at the first end part of the rotary shaft in the first direction. The rotary shaft has a first hole and a second hole. The first hole has a first opening at the first end part of the rotary shaft, and extends in the lateral direction. The second communicates with the first hole and extends in a direction crossing the axis of the rotary shaft. The second hole has a second opening on an outer peripheral surface of the rotary shaft. A spiral part is arranged in the first hole.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to power tools.

Background Art

[0002] In power tools, a lubricant may be introduced into the housing in order to suppress wear of members housed in the housing. Patent Document 1 describes a hammer drill in which a storage portion for a lubricant is formed in a region between a drive shaft and a bearing element. In this hammer drill, by sealing the storage portion with a seal member, outflow of the lubricant from the storage portion is suppressed. Thereby, lubrication between the drive shaft and the bearing element is achieved, and wear is suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regardless of the technique of Patent Document 1, in a power tool in which a lubricant is introduced into the housing, a technique capable of suppressing wear of parts in the housing has been demanded.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following aspects.

[0006] According to one aspect of the present disclosure, a power tool is provided. The power tool includes a rotating shaft and a housing. The rotating shaft has a first end portion located on the first direction side in the axial direction of the rotating shaft and a second end portion located on the second direction side opposite to the first direction side. The rotating shaft is configured to be rotationally driven by a motor. The housing houses the rotating shaft. A lubricant is introduced into the interior of the housing. The housing is configured to be able to store the lubricant on the first direction side of the first end portion of the rotating shaft. In other words, the housing is configured to be able to store the lubricant in a space region of the interior space of the housing where the first end portion of the rotating shaft is disposed. It can also be said that the housing is configured to be able to store the lubricant between the first end portion of the rotating shaft and a wall disposed on the first direction side of the first end portion among the walls of the housing. The rotating shaft has a first hole and a second hole. The first hole has a first opening at the first end portion of the rotating shaft and is configured to extend in the axial direction of the rotating shaft. The second hole communicates with the first hole on the second direction side of the first opening. The second hole extends in a direction intersecting the axis of the rotating shaft and is configured to have a second opening on the outer peripheral surface of the rotating shaft. A helical portion is provided in the first hole.

[0007] According to this aspect, when the user performs an operation using a power tool with the first end of the rotating shaft directed vertically downward or in a direction close thereto, the lubricant in the housing can move within the housing by gravity and be stored on the first direction side of the first end of the rotating shaft. The rotating shaft has a first opening at the first end and a first hole extending in the axial direction of the rotating shaft, and a helical portion is provided in the first hole. Therefore, by utilizing the rotation of the rotating shaft and the helical shape of the helical portion, the stored lubricant can be introduced from the first opening and moved in the first hole toward the second direction side (vertically upward or in a direction close thereto). Further, the rotating shaft includes a second hole that communicates with the first hole, extends in a direction intersecting the axis of the rotating shaft, and has a second opening on the outer peripheral surface of the rotating shaft. Therefore, the lubricant in the first hole can be discharged from the second opening of the second hole. Accordingly, during the operation using the power tool, the lubricant can be spread over the rotating shaft and around the rotating shaft. As a result, wear of the components constituting the power tool can be suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] Hereinafter, representative and non-limiting specific examples of the present disclosure will be described in detail with reference to the drawings. This detailed description is merely intended to show those skilled in the art the details for implementing preferred examples of the present disclosure, and is not intended to limit the scope of the present disclosure. Further, the additional features and disclosures disclosed below can be used separately or together with other features and disclosures to provide further improved power tools, their manufacturing methods, and usage methods.

[0010] Also, the combinations of features and steps disclosed in the following detailed description are not essential for implementing the present disclosure in the broadest sense, and are described only for the purpose of explaining representative specific examples of the present disclosure in particular. Further, the various features of the above and below representative specific examples, as well as the various features described in the independent and dependent claims, do not have to be combined as described in the specific examples here or in the order listed when providing additional and useful embodiments of the present disclosure.

[0011] All features described in this specification and / or the claims are intended to be disclosed separately and independently of each other as limitations to the initial disclosure and the claimed specific matters, apart from the configurations of the features described in the embodiments and / or the claims. Further, all descriptions regarding numerical ranges and groups or populations are made with the intention of disclosing intermediate configurations as limitations to the initial disclosure and the claimed specific matters.

[0012] In one embodiment of the present disclosure, the helical portion may be formed as a separate member from the rotating shaft. The helical portion may be inserted into the first hole and fixed to the housing.

[0013] According to the above embodiment, a spiral portion is inserted into the first hole, and the spiral portion is fixed to the housing (that is, the spiral portion is configured not to rotate integrally with the rotating shaft). Thus, the lubricant stored on the first direction side of the first end portion of the rotating shaft can be introduced from the first opening into the first hole and moved to the rear portion of the first hole, and discharged from the second opening of the second hole. Therefore, during the operation using the power tool, the lubricant can be spread over the rotating shaft and around the rotating shaft.

[0014] In addition to or instead of the above embodiment, the power tool may include a holder. The holder may be configured to be able to fix the spiral portion to the housing.

[0015] According to the above embodiment, the spiral portion can be stably fixed to the housing. Also, during the operation using the power tool, it is possible to suppress changes in the arrangement of the spiral portion with respect to the housing and the arrangement of the spiral portion with respect to the rotating shaft.

[0016] In addition to or instead of the above embodiment, the spiral portion may be provided in the first hole and configured to be rotatable integrally with the rotating shaft.

[0017] According to the above embodiment, the spiral portion is provided in the first hole, and with the configuration that it can rotate integrally with the rotating shaft, the lubricant stored on the first direction side of the first end portion of the rotating shaft can be introduced from the first opening into the first hole and moved to the second direction side of the first hole, and discharged from the second opening of the second hole. Therefore, during the operation using the power tool, the lubricant can be spread over the rotating shaft and around the rotating shaft.

[0018] In addition to or instead of the above embodiment, the tip of the spiral portion may protrude from the first opening of the rotating shaft toward the first direction.

[0019] According to the above embodiment, the tip of the spiral portion protrudes from the first opening of the rotating shaft toward the first direction side, that is, into the space region where the lubricant can be stored within the housing. Therefore, the tip of the spiral portion can function as a guide for introducing the lubricant into the first hole. Accordingly, the lubricant can be spread over the rotating shaft and around the rotating shaft relatively early from the start of the operation using the power tool, so that wear of the components constituting the power tool can be more effectively suppressed.

[0020] In addition to, or in place of, the above embodiment, the power tool may be a percussion tool configured to be capable of performing at least a percussion operation. The power tool may include a final output shaft and a drive mechanism. The final output shaft may be configured to removably hold a tip tool and extend parallel to the rotating shaft. The drive mechanism may include the rotating shaft, a rotating body, and a swinging body. The rotating body may be provided on the rotating shaft and configured to be rotatable integrally with the rotating shaft. The swinging body may be configured to swing in the axial direction of the rotating shaft by the rotation of the rotating body. The drive mechanism may be configured to linearly drive the tip tool along the axis of the final output shaft when the swinging body swings. The second opening may be provided inside the rotating body.

[0021] According to the above embodiment, when the user performs a percussion operation of using the percussion tool to strike a workpiece with the tip tool of the percussion tool directed vertically downward or in a direction close thereto, the lubricant is supplied between the rotating shaft and the rotating body, so that wear between the rotating shaft and the rotating body can be effectively suppressed. Also, the rotating shaft, which is a part of the drive mechanism, can exhibit the function of supplying the lubricant between the rotating shaft and the rotating body and around the rotating shaft. Therefore, it is possible to suppress the complication of the configuration of the percussion tool and the increase in the number of components constituting the percussion tool and the enlargement of the outer contour of the percussion tool in order to supply the lubricant and achieve component circulation.

[0022] In addition to or instead of the above-described embodiment, the power tool may include a switching member. The switching member may be configured to switch between a state in which the rotating body rotates integrally with the rotating shaft and the power tool can perform the striking operation, and a state in which the rotating body does not rotate integrally with the rotating shaft and the power tool cannot perform the striking operation.

[0023] According to the above-described embodiment, since the lubricant is discharged from the second opening to the inside of the rotating body, it is possible to provide a power tool that can switch between a state in which the striking operation can be performed and a state in which the striking operation cannot be performed while suppressing wear between the rotating body and the rotating shaft.

[0024] In addition to or instead of the above-described embodiment, the rotating body may include at least one third hole. The third hole may be configured to extend in a direction intersecting the axis of the rotating shaft and have openings in the inner peripheral surface and the outer peripheral surface of the rotating body, respectively.

[0025] According to the above-described embodiment, the lubricant discharged from the second opening of the rotating shaft moves into the third hole provided in the rotating body and is discharged from the opening provided in the outer peripheral surface of the rotating body to the periphery of the rotating body (inside the housing). Therefore, during the machining operation with the first end portion of the rotating shaft directed vertically downward or in a direction close thereto, the lubricant can be spread between the rotating shaft and the rotating body and around the rotating body. As a result, wear of the components constituting the power tool can be further suppressed by the machining operation. Further, wear of the components constituting the power tool can be effectively suppressed by using the rotating shaft and the rotating body provided in the power tool.

[0026] In addition to or instead of the above-described embodiment, the at least one third hole may include two third holes. The two third holes may be provided so as to face each other with the rotating shaft interposed therebetween. In other words, the two third holes may extend along a straight line intersecting the rotating shaft.

[0027] According to the above embodiment, since the two third holes are provided so as to face each other with the rotating shaft interposed therebetween, it is possible to suppress the occurrence of unbalance in the rotating body while discharging the lubricant from the rotating body. Therefore, the rotating body can be stably rotated on the rotating shaft.

[0028] In addition to, or in place of, the above embodiment, the lubricant may be grease.

[0029] According to the above embodiment, since grease has relatively high viscosity, it is possible to suppress the excessive requirement for the accuracy of the sealing mechanism for suppressing the leakage of the lubricant from the housing in the power tool.

[0030] Hereinafter, with reference to FIGS. 1 to 5, a power tool according to an embodiment will be described. In the present embodiment, a hammer drill 101 is exemplified as the power tool. The hammer drill 101 is a hand-held electric tool used for machining operations such as chipping work and drilling work, and performs an operation of linearly driving the tip tool 91 along a predetermined drive shaft A1 (hereinafter referred to as a striking operation), and an operation of rotationally driving the tip tool 91 around the drive shaft A1 (hereinafter referred to as a rotational operation).

[0031] First, the schematic configuration of the hammer drill 101 will be briefly described. As shown in FIG. 1, the outer shell of the hammer drill 101 is mainly formed by a main body housing 10 and a handle 17 connected to the main body housing 10.

[0032] The main body housing 10 is a hollow body also referred to as a tool body or an outer shell housing. As shown in FIG. 2, the main body housing 10 mainly houses a spindle 31, a motor 2, and a drive mechanism 5.

[0033] The spindle 31 is a long cylindrical member. A tool holder 32 is provided at one end of the spindle 31. The tool holder 32 is formed to removably hold the tip tool 91. The major axis of the spindle 31 defines the drive axis A1 of the tip tool 91. The main body housing 10 extends along this drive axis A1. The tool holder 32 is disposed within one end portion of the main body housing 10 in the extending direction of the drive axis A1.

[0034] As shown in FIG. 1, the handle 17 is a long hollow body that is gripped by the user. One axial end portion of the handle 17 is connected to the other end portion of the main body housing 10 (the end portion on the side opposite to the side where the tool holder 32 is disposed). The handle 17 extends in a direction intersecting the drive axis A1 (specifically, a direction substantially perpendicular) so as to protrude from the other end portion of the main body housing 10. A power cord 179 connectable to an external AC power supply extends from the protruding end of the handle 17. The handle 17 has a trigger 171 that is pressed (pulled) by the user, and a switch (not shown) that is turned on in response to the pressing operation of the trigger 171.

[0035] When the trigger 171 is pressed and the switch is turned on, the motor 2 is energized and the drive mechanism 5 is driven. In the hammer drill 101 of the present embodiment, when the drive mechanism 5 is driven, a striking operation and / or a rotating operation is performed.

[0036] Hereinafter, the detailed configuration of the hammer drill 101 will be described. In the following description, for convenience, the extending direction of the drive axis A1 is defined as the front-rear direction of the hammer drill 101. In the front-rear direction, the one end portion side where the tool holder 32 is disposed is defined as the front side of the hammer drill 101, and the opposite side (the side where the handle 17 is connected) is defined as the rear side. Also, the direction perpendicular to the drive axis A1 and corresponding to the axial direction of the handle 17 is defined as the up-down direction of the hammer drill 101. In the up-down direction, the side where the handle 17 is connected to the main body housing 10 is defined as the upper side, and the protruding end side of the handle 17 is defined as the lower side. Further, the direction perpendicular to the front-rear direction and the up-down direction is defined as the left-right direction.

[0037] As shown in FIGS. 1 and 2, the front end portion of the main body housing 10 is formed in a cylindrical shape. This cylindrical portion is also referred to as the barrel portion 131. Among the main body housing 10, the portion other than the barrel portion 131 is formed in a substantially rectangular box shape.

[0038] As shown in FIG. 2, a hollow inner housing 14 is disposed inside the main body housing 10. The inner housing 14 has a front wall 143, a rear wall 145, and a peripheral wall 144. The rear wall 145 also functions as a support for supporting various bearings. The rear wall 145 is disposed so as to intersect the drive shaft A1. The inner housing 14 is fitted into the inner periphery of the main body housing 10 and is fixedly held by the main body housing 10.

[0039] A seal ring 141 is interposed between the outer periphery of the front wall 143 of the inner housing 14 and the inner periphery of the main body housing 10. Lubricant is introduced into the portion of the main body housing 10 on the front side of the seal ring 141 and the inner housing 14. The portion of the main body housing 10 on the front side of the seal ring 141 and the inner housing 14 are also referred to as the lubricant storage portion 16. The seal ring 141 suppresses the leakage of the lubricant to the outside of the lubricant storage portion 16. A motor 2 is mainly housed in the region on the rear side of the inner housing 14 (rear wall 145). A spindle 31 and a drive mechanism 5 are mainly housed in the region on the front side of the rear wall 145 (lubricant storage portion 16). Note that most of the drive mechanism 5 and the rear end portion of the spindle 31 are housed in the inner housing 14. In the present embodiment, grease having a higher viscosity than oil is adopted as the lubricant.

[0040] Hereinafter, the internal structure of the main body housing 10 will be described. As shown in FIG. 2, the main body housing 10 mainly houses a spindle 31, a motor 2, a drive mechanism 5, and a clutch cam 61.

[0041] The spindle 31 is disposed within the lubricant storage portion 16 and extends in the front-rear direction. The spindle 31 is configured as an elongated stepped cylindrical member. The spindle 31 is rotatably supported about the drive shaft A1 by two bearings.

[0042] As described above, the front half portion of the spindle 31 constitutes a tool holder 32 to which the tip tool 91 can be attached and detached. The rear half portion of the spindle 31 constitutes a cylinder 33 that slidably holds a piston 55 described later. In the present embodiment, the spindle 31 is a single member in which the tool holder 32 and the cylinder 33 are integrally formed. In other embodiments, the spindle 31 may be formed by connecting a plurality of members.

[0043] The motor 2 is housed in a portion of the main body housing 10 that is on the rear side of the inner housing 14 (rear wall 145). Although detailed illustration is omitted, the motor 2 includes a motor main body portion including a stator and a rotor, and a motor shaft extending from the rotor. The rotation axis A2 of the motor shaft is below the drive shaft A1 and extends parallel to the drive shaft A1 (in the front-rear direction). In the present embodiment, an AC motor that is driven by receiving power supply from an external power source via a power cord 179 is employed as the motor 2. In other embodiments, the motor 2 may be a DC motor that is driven by receiving power supply from a battery pack. The front end portion of the motor shaft penetrates the rear wall 145 and protrudes into the inner housing 14.

[0044] As shown in FIG. 2, the drive mechanism 5 includes a rotating shaft 40, a motion conversion mechanism 51, and a striking element 57. The drive mechanism 5 is configured to be capable of performing an operation (striking operation) of linearly driving the tip tool 91 along the front-rear direction.

[0045] The rotating shaft 40 extends in the front-rear direction within the lubricant storage portion 16. That is, the rotation axis A3 of the rotating shaft 40 extends parallel to the drive shaft A1 and the rotation axis A2. The rotating shaft 40 is rotatably supported around the rotation axis A3 via two bearings. Among these two bearings, the front bearing is held by the inner housing 14, and the rear bearing 414 is held by the rear wall 145. As shown in FIG. 3, the front end portion 41 of the rotating shaft 40 protrudes forward from the front wall 143 of the inner housing 14 and faces the front wall 161 of the main body housing 10 (lubricant storage portion 16). Note that the space where the front end portion 41 is disposed is a space in the internal space of the lubricant storage portion 16 where lubricant is likely to accumulate due to gravity when the front end of the hammer drill 101 is directed vertically downward or in a direction close thereto. A driven gear 411 is fixed to the rear end portion 42 of the rotating shaft 40. The driven gear 411 meshes with a pinion gear (not shown) fixed to the front end portion of the motor shaft, and the rotating shaft 40 rotates as the motor shaft rotates.

[0046] The motion conversion mechanism 51 is configured to convert the rotational motion of the rotating shaft 40 into a linear motion and transmit it to the striking element 57. The motion conversion mechanism 51 includes a rotating body 53, a swing body 54, and a piston 55.

[0047] As shown in FIG. 3, the rotating body 53 is selectively rotatably disposed on the rotating shaft 40 (around the rotating shaft 40). External teeth 531 (clutch teeth) are provided on the outer periphery at the front end portion of the rotating body 53.

[0048] The rocking body 54 is operably connected to the rotating body 53 via rolling elements 541 disposed on the outer peripheral portion of the rotating body 53. The rotating body 53, the rolling elements 541, and the rocking body 54 are collectively also referred to as a swash bearing. The rocking body 54 rocks in the front-rear direction as the rotating body 53 rotates. As shown in FIG. 2, the piston 55 is formed in a bottomed cylindrical shape and is held in the cylinder 33 so as to be movable in the front-rear direction. The piston 55 is operably connected to the rocking body 54 and reciprocates in the front-rear direction as the rocking body 54 rocks.

[0049] As shown in FIG. 2, the striking element 57 is configured to linearly operate to strike the tip tool 91, thereby driving the tip tool 91 linearly along the drive shaft A1. The striking element 57 includes a striker 58 and an impact bolt 59. The striker 58 is disposed in the piston 55 so as to be slidable in the front-rear direction. The impact bolt 59 is disposed in front of the striker 58. The space (air chamber) inside the piston 55 behind the striker 58 functions as an air spring.

[0050] When the rotating body 53 rotates and the piston 55 is moved forward as the rocking body 54 rocks, the air in the air chamber is compressed and the internal pressure rises. The striker 58 is pushed forward at high speed by the action of the air spring and collides with the impact bolt 59, transmitting kinetic energy to the tip tool 91. Thereby, the tip tool 91 is linearly driven along the drive shaft A1 to strike the workpiece. On the other hand, when the piston 55 is moved rearward as the rocking body 54 rocks, the air in the air chamber expands and the internal pressure decreases, and the striker 58 is drawn rearward. In this way, the drive mechanism 5 can repeatedly perform the striking operation.

[0051] The clutch cam 61 is configured to switch between a state where the rotating shaft 40 rotates integrally with the rotating body 53 and a state where the rotating shaft 40 does not rotate integrally with the rotating body 53. As shown in FIG. 3, the clutch cam 61 is disposed on the rotating shaft 40. The clutch cam 61 is spline-coupled to the outer periphery of the rotating shaft 40 on the front side of the rotating body 53. The clutch cam 61 is substantially immovable in the circumferential direction with respect to the rotating shaft 40 and is movable in the extending direction (front-rear direction) of the rotation axis A3. The clutch cam 61 is operably connected to a change lever 800 (see FIGS. 1 and 5) that can be operated by the user. When the change lever 800 is operated, the clutch cam 61 moves in the front-rear direction on the rotating shaft 40.

[0052] As shown in FIG. 3, when the clutch cam 61 is moved to the rear position (engagement position) where the internal teeth 611 of the clutch cam 61 and the external teeth 531 of the rotating body 53 are engaged, the rotating body 53 rotates integrally with the rotating shaft 40. At this time, the swing body 54 swings due to the rotation of the rotating body 53, and the drive mechanism 5 performs a striking operation. Also, as shown in FIG. 4, when the clutch cam 61 is moved forward (non-engagement position) from the engagement position, the engagement between the internal teeth 611 of the clutch cam 61 and the external teeth 531 of the rotating body 53 is released. Thereby, the rotating body 53 becomes unable to rotate integrally with the rotating shaft 40. At this time, the drive mechanism 5 does not perform a striking operation. Thus, the clutch cam 61 switches between a state where the drive mechanism 5 can perform a striking operation and a state where the drive mechanism 5 cannot perform a striking operation.

[0053] Although detailed illustration and description are omitted, a rotary transmission mechanism for transmitting rotation from the motor 2 to the spindle 31 is separately provided in the hammer drill 101. By operating the change lever 800 by the user, the state where the rotation of the motor 2 is transmitted to the spindle 31 by the rotary transmission mechanism and the state where it is not transmitted can be switched. When the rotation of the motor 2 is transmitted to the spindle 31, the tip tool 91 is rotationally driven. Further, the hammer drill 101 is configured to be operable in any one of a rotary percussion mode in which both the rotary operation by the rotary transmission mechanism and the percussion operation by the drive mechanism 5 are performed, a rotation-only mode in which only the rotary operation is performed, and a percussion-only mode in which only the percussion operation is performed. These operation modes can be switched by operating the change lever 800.

[0054] As shown in FIGS. 3 to 5, the hammer drill 101 further includes a first hole 81 and a second hole 82 provided in the rotary shaft 40, a spiral member 71 inserted into the first hole 81, and a third hole 83 provided in the rotating body 53. In the hammer drill 101, appropriate lubrication of the components inside the lubricant storage portion 16 is achieved by these configurations.

[0055] As shown in FIGS. 3 and 4, the first hole 81 has a first opening 811 at the front end portion 41 of the rotary shaft 40 and extends in the front-rear direction. The axis of the first hole 81 coincides with the rotation axis A3 of the rotary shaft 40. Note that the first hole 81 does not penetrate the rotary shaft 40 in the front-rear direction, and the rear end 812 of the first hole 81 is located inside the rotary shaft 40.

[0056] The second hole 82 communicates with the first hole 81 on the rear side of the first opening 811 and extends in the radial direction of the rotary shaft 40. In the present embodiment, the second hole 82 communicates with the first hole 81 in the vicinity of the rear end 812 of the first hole 81. The second hole 82 has a second opening 821 on the outer peripheral surface of the rotary shaft 40. The second opening 821 is provided inside the rotating body 53.

[0057] In addition, a gap G is provided between the outer peripheral surface of the rotating shaft 40 and the inner peripheral surface of the rotating body 53. In the present embodiment, the gap G includes a first gap G1 and a second gap G2. In the present embodiment, a plurality of grooves 45 extending in the axial direction A3 (front-rear direction) are provided on the outer peripheral surface of the rotating shaft 40 in the circumferential direction. The groove 45 extends from the position where the rotating body 53 is disposed to the front side of the rotating body 53. The first gap G1 can be defined by the groove 45 and the inner peripheral surface of the rotating body 53. Further, the inner diameter of the rotating body 53 is slightly larger in a part including the location where the rotating body 53 faces the second opening 821. The second gap G2 can be defined by the inner peripheral surface of the portion where the inner diameter of the rotating body 53 is slightly larger and the outer peripheral surface of the rotating shaft 40. The second gap G2 is larger than the first gap G1. It can also be said that the second hole 82 opens into the second gap G2.

[0058] The helical member 71 has a helical shaft portion 711. The shaft portion 711 is provided in the first hole 81 and extends in the front-rear direction. In the present embodiment, the helical member 71 is formed as a separate member from the rotating shaft 40. The helical member 71 can be formed, for example, by sheet metal working. Note that a compression spring may be used as the helical member 71. The helical shape of the shaft portion 711 is formed at an interval such that when a lubricant is supplied from the first opening 811 to the first hole 81 and the rotating shaft 40 rotates, the lubricant can move rearward along the shaft portion 711. The first hole 81 of the rotating shaft 40 (the inner peripheral wall of the rotating shaft 40 that defines the first hole 81) and the helical member 71 (the shaft portion 711) constitute a so-called Archimedean screw.

[0059] In the present embodiment, the tip end portion 712 of the helical member 71 (the shaft portion 711) protrudes forward from the first opening 811. The tip end portion 712 is located between the front end portion 41 of the rotating shaft 40 and the wall (front wall 161) of the main body housing 10 on the front side of the front end portion 41. As shown in FIG. 5, the tip end portion 712 of the helical member 71 has a bent portion 714 bent in a hook shape.

[0060] In the present embodiment, a holder 75 for fixing the helical member 71 to the lubricant storage portion 16 is disposed around the front end portion 41 of the rotary shaft 40. As shown in FIG. 5, the holder 75 has a locking groove 755 into which the bent portion 714 of the helical member 71 can be locked, and a fixing portion 753 that can be fixed to the front wall 143 of the inner housing 14. The holder 75 is formed such that the axis of the insertion hole 751 provided at the front end of the holder 75 coincides with the axis of the first hole 81 (the rotation axis A3 of the rotary shaft 40) in a state where the fixing portion 753 is fixed to the front wall 143. By inserting the rear end portion 713 of the shaft portion 711 into the insertion hole 751 of the holder 75 and locking the bent portion 714 in the locking groove 755, the helical member 71 is fixed to the inner housing 14 via the holder 75. As a result, the helical member 71 does not rotate as the rotary shaft 40 rotates.

[0061] The rotating body 53 has a third hole 83. The third hole 83 has openings 831 and 832 on the inner peripheral surface and the outer peripheral surface of the rotating body 53, respectively, and extends in a direction intersecting the axis of the rotating body 53 (the rotation axis A3 of the rotary shaft 40). In the present embodiment, the rotating body 53 has two third holes 83. The two third holes 83 face each other with the rotary shaft 40 interposed therebetween. That is, the two third holes 83 extend along a straight line intersecting the rotation axis A3. The opening 831 on the inner peripheral surface of the rotating body 53 is provided in a portion of the inner peripheral surface of the rotating body 53 that defines the second gap G2. The opening 832 on the outer peripheral surface of the rotating body 53 is provided in a portion of the outer peripheral surface of the rotating body 53 where the orbit of the rolling element 541 is not arranged.

[0062] Hereinafter, a mode in which lubrication of the components constituting the hammer drill 101 is achieved will be described in combination with the effects exhibited by the hammer drill 101 of the present embodiment.

[0063] For example, when performing floor chipping work or drilling work, if the tip tool 91 of the hammer drill 101 (that is, the front end portion 41 of the rotating shaft 40) is directed vertically downward or in a direction close thereto, the lubricant in the lubricant storage portion 16 will move by gravity to the front side portion of the lubricant storage portion 16 (the front side portion of the front end portion 41 of the rotating shaft 40) and may stay in this portion. When the upper surface (interface) of the lubricant reaches the front end portion 41 (the first opening 811) of the rotating shaft 40, the lubricant moves backward in the hammer drill 101 through the first hole 81 according to the principle of the Archimedean screw. The lubricant that has moved backward through the first hole 81 is discharged from the second opening 821 of the second hole 82 and spreads over the rotating shaft 40. More specifically, the lubricant is discharged from the second opening 821 into the second gap G2, moves through the first gap G1 (along the groove 45), and spreads over the rotating shaft 40. Therefore, wear between the parts on the rotating shaft 40 such as the rotating body 53, the clutch cam 61, and the bearings of the rotating shaft 40 and the rotating shaft 40 can be suppressed. Also, due to the rotation of the rotating shaft 40, the lubricant can be supplied around the rotating shaft 40. Thereby, wear between the parts on the rotating shaft 40 and the rotating shaft 40, and wear of the parts around the rotating shaft 40 can be suppressed, and the long life of these can be achieved.

[0064] Also, the lubricant discharged from the second opening 821 into the second gap G2 flows into the third hole 83 through the opening 831 of the rotating body 53 and is discharged into the lubricant storage portion 16 from the opening 832. At this time, due to the rotation of the rotating body 53, the lubricant is scattered from the opening 832 into the lubricant storage portion 16. Therefore, wear between the parts on the rotating body 53 such as the rolling elements 541 and the rocking body 54 and the rotating body 53, and wear of other parts in the lubricant storage portion 16 such as the piston 55 can be suppressed, and the long life of these can be achieved.

[0065] In addition, the drive mechanism 5 of the hammer drill 101 is configured to perform a striking operation by converting the rotation of the rotary shaft 40 into linear motion and transmitting it to the tip tool 91 held by the spindle 31. That is, the rotary shaft 40, which is a part of the drive mechanism 5, can exhibit a function of circulating the lubricant within the lubricant storage portion 16. Therefore, in order to circulate the lubricant and achieve component circulation, it is possible to suppress the complication of the configuration of the hammer drill 101 and the increase in the number of components constituting the hammer drill 101, which would otherwise enlarge the outer contour of the hammer drill 101.

[0066] In the present embodiment, the tip portion 712 of the helical member 71 protrudes forward from the first opening 811. Therefore, the tip portion 712 of the helical member 71 can function as a guide for introducing the lubricant into the first hole 81. Accordingly, in the hammer drill 101 of the present embodiment, the lubricant can be spread over the rotary shaft 40 and around the rotary shaft 40 relatively early from the start of the operation, so that wear of the components constituting the hammer drill 101 can be further suppressed.

[0067] The lubricant discharged from the second opening 821 of the second hole 82 and the lubricant discharged from the opening of the third hole 83 are supplied to the clutch cam 61. Therefore, the clutch cam 61 can move smoothly on the rotary shaft 40. In addition, wear between the internal teeth 611 of the clutch cam 61 and the external teeth 531 of the rotating body 53 can be suppressed. Accordingly, since the engaged state and the disengaged state between the clutch cam 61 and the rotating body 53 can be switched smoothly, in the hammer drill 101, it is possible to smoothly switch between a mode in which a striking operation is possible (rotary striking mode, striking only mode) and a mode in which a striking operation is impossible (rotation only mode).

[0068] In addition, the rotating body 53 is provided with two third holes 83 provided so as to face each other with the rotary shaft 40 interposed therebetween. Therefore, while discharging the lubricant from the rotating body 53, it is possible to suppress the occurrence of imbalance in the rotating body 53. Therefore, the rotating body 53 can be stably rotated on the rotary shaft 40.

[0069] Further, the helical member 71 is configured as a member separate from the rotating body 53 and is inserted into the first hole 81. Therefore, for example, compared with providing a helical groove on the inner wall of the first hole 81, a configuration (Archimedean screw) for moving the lubricant rearward in the first hole 81 can be easily manufactured. Further, since the helical member 71 is fixed to the lubricant storage portion 16 (inner housing 14) by the holder 75, the fixing state of the helical member 71 with respect to the lubricant storage portion 16 can be stabilized.

[0070] In the present embodiment, grease is employed as the lubricant. Generally, grease has relatively high viscosity. Therefore, it is possible to suppress the leakage of the lubricant from the lubricant storage portion 16 by a simple configuration in which a seal ring 141 is interposed between the outer periphery of the inner housing 14 and the inner periphery of the main body housing 10.

[0071] The correspondence between each component of the above embodiment and each component of the technology of the present disclosure is shown below. However, each component of the embodiment is merely an example and does not limit each component of the technology of the present disclosure. The hammer drill 101 is an example of a "power tool" and a "striking tool". The motor 2 is an example of a "motor". The rotating shaft 40 is an example of a "rotating shaft". The axis A3 of the rotating shaft 40 is an example of an "axis of a rotating shaft". The extending direction (front-rear direction) of the rotating axis A3 is an example of an "axial direction of a rotating shaft", and the front side and the rear side are examples of a "first direction side" and a "second direction side", respectively. The front end portion 41 and the rear end portion 42 of the rotating shaft 40 are examples of a "first end portion" and a "second end portion", respectively. The lubricant storage portion 16 (main body housing 10, inner housing 14) is an example of a "housing". The first opening 811 is an example of a "first opening". The first hole 81 is an example of a "first hole". The second opening 821 is an example of the "second opening". The second hole 82 is an example of the "second hole". The radial direction of the rotating shaft 40 is an example of the "direction intersecting the axis of the rotating shaft". The spiral member 71 and the shaft portion 711 are examples of the "spiral portion". The holder 75 is an example of the "holder". The tip portion 712 is an example of the "tip portion". The tip tool 91 is an example of the "tip tool". The spindle 31 is an example of the "final output shaft". The drive shaft A1 is an example of the "axis of the final output shaft". The drive mechanism 5 is an example of the "drive mechanism". The rotating body 53 is an example of the "rotating body". The oscillating body 54 is an example of the "oscillating body". The clutch cam 61 is an example of the "switching member". The third hole 83, the openings 831 and 832 are examples of the "third hole" and the "opening", respectively.

[0072] Note that the above embodiments are merely illustrative, and the power tool according to the present disclosure is not limited to the hammer drill 101 illustrated in the above embodiments. For example, non-limiting changes illustrated below can be made. Also, at least one of these changes can be adopted in combination with at least a part of the configuration (features) of the hammer drill 101 and at least one of the configurations (features) described in the claims.

[0073] The mechanism of providing the first hole 81 and the second hole 82 in the rotating shaft 40 and arranging a spiral portion in the first hole 81 to circulate the lubricant, which was described in the above embodiment, is not limited to the hammer drill 101, and may be applied to other power tools having a rotating shaft rotated by a motor.

[0074] The first hole 81 may be provided not only in the rotating shaft 40 of the above embodiment, but also in a shaft that rotates by the power of the motor 2. For example, a spiral portion and the first hole 81 may be provided in an extended portion of the motor shaft or in the final output shaft to which the rotational power of the motor 2 is output. In this case, the extended portion of the motor shaft or the final output shaft can function as a rotating shaft for circulating the lubricant.

[0075] The rear end 812 of the first hole 81 does not necessarily have to be located within the rotating shaft 40, and the first hole 81 may penetrate the rotating shaft 40 in the direction of the axis A3. Further, the second hole 82 only needs to communicate with the rear part of the first opening 811 of the first hole 81, and does not necessarily have to communicate with the rear end 812 of the first hole 81. Furthermore, at least one second hole 82 may be provided in the rotating shaft 40, and the rotating shaft 40 may have two or more second holes 82. The second hole 82 does not necessarily have to extend in the radial direction of the rotating shaft 40, and may extend in a direction intersecting the axis A3 of the rotating shaft 40. Even with these configurations, the lubricant discharged from the second opening 821 of the 2 hole 8 2 can be spread over the rotating shaft 40. Also, due to the rotation of the rotating shaft 40, the lubricant on the rotating shaft 40 can be scattered around the rotating shaft 40. Note that, as in the above embodiment, by configuring the rear end 812 of the first hole 81 to be located within the rotating shaft 40 and the second hole 82 to communicate with the first hole 81 near the rear end 812 of the first hole 81, it is possible to prevent the lubricant from staying in the first hole 81 or being discharged from a portion other than the second opening 821. Therefore, there is an advantage that the lubricant flowing into the first hole 81 from the first opening 811 can be supplied without waste to the portion where lubrication is required.

[0076] The rotating body 53 does not necessarily have to have the third hole 83. Even with this configuration, the 2 hole 8 2The lubricant discharged from the second opening 821 can be spread over the rotating shaft 40. Further, by the rotation of the rotating shaft 40, the lubricant on the rotating shaft 40 can be scattered around the rotating shaft 40.

[0077] When providing the third hole 83 in the rotating body 53, the number thereof may be one or three or more. The position and the extending direction of the third hole 83 (opening 832) can be changed as appropriate.

[0078] The helical member may rotate integrally with the rotating shaft 40. As shown in FIG. 6, the shaft portion 711 of the helical member 71A is inserted into the first hole 81, and the rear end portion 713A of the shaft portion 711 is fixed to the rear end 812 of the first hole 81, and the helical member 71A may be configured to rotate integrally with the rotating shaft 40. In this case, the tip portion 712A of the helical member 71A may not have the bent portion 714, and the hammer drill 101A may not include the holder 75. In this form, even if the upper surface (interface) of the lubricant that has moved to the front portion of the lubricant storage portion 16 has not reached the first opening 811, if it has reached the tip portion 712A of the helical member 71A, the lubricant can be introduced from the first opening 811 into the first hole 81 through the tip portion 712A by the rotation of the helical member 71A (tip portion 712A).

[0079] The rotating shaft 40 and the helical portion do not have to be separate members. For example, a helical groove may be provided on the inner wall of the rotating shaft 40, and the helical portion may rotate integrally with the rotating shaft 40. Also with this form, the lubricant can be moved rearward in the first hole 81 and discharged from the second opening 821 of the second hole 82, so that the lubrication of the components constituting the hammer drill 101 can be achieved.

[0080] The arrangement relationship among the rotating shaft 40, the motor 2 (motor shaft), and the final output shaft (spindle 31) is not limited to the arrangement of the above-described embodiment. For example, the rotation axis A3 of the rotating shaft 40 may intersect with the drive axis A1 or the rotation axis A2 of the motor shaft. Also in this form, if the user directs the front end portion 41 of the rotating shaft 40 vertically downward or in a direction close thereto and performs work using the power tool, the lubricant moves within the first hole 81 along the spiral portion provided in the first hole 81 and is discharged onto the rotating shaft 40 from the second opening 821. Therefore, wear of the rotating shaft 40 and members around the rotating shaft 40 can be suppressed.

[0081] Furthermore, in view of the gist of the present disclosure and the above-described embodiment, the following aspects are constructed. At least one of the following aspects can be adopted in combination with at least one of the above-described embodiment, its modification, and the configurations (features) described in each claim. [Aspect 1] The switching member is rotatably disposed on the rotating shaft integrally with the rotating shaft and movable in the front-rear direction on the rotating shaft, and is configured to integrally rotate the rotating shaft and the rotating body by being moved to an engagement position that engages with the rotating body in the front-rear direction, and to not integrally rotate the rotating shaft and the rotating body by being moved to a position where the engagement with the rotating body is released. [Aspect 2] The rotating body is disposed on the rotating shaft with a gap provided between the rotating body and the rotating shaft, and the second hole opens toward the gap. [Aspect 3] The gap is formed by an inner peripheral surface of a portion where the inner diameter of the rotating body is formed to be large and an outer peripheral surface of the rotating shaft, and includes a second 2 gap. [Aspect 4] The gap is formed by a groove provided on the outer peripheral surface of the rotating shaft and an inner peripheral surface of the rotating body, and includes a second 1 gap. [Aspect 5] The second gap is larger than the first gap.

Explanation of Signs

[0082] 2: Motor, 5: Driving mechanism, 10: Main body housing, 131: Barrel part, 14: Inner housing, 141: Seal ring, 143: Front wall, 144: Peripheral wall, 145: Rear wall, 16: Lubricant storage part, 161: Front wall, 17: Handle, 171: Trigger, 179: Power cord, 31: Spindle, 32: Tool holder, 33: Cylinder, 40: Rotating shaft, 41: Front end part, 42: Rear end part, 45: Groove, 51: Motion conversion mechanism, 53: Rotating body, 531: External teeth, 54: Oscillating body, 541: Rolling element, 55: Piston, 57: Striking element, 58: Striker, 59: Impact bolt, 61: Clutch cam, 611: Internal teeth, 71, 71A: Helical member, 711: Shaft part, 712, 712A: Tip part, 713, 713A: Rear end part, 714: Bending part, 75: Holder, 751: Insertion hole, 753: Fixing part, 755: Locking groove, 81: First hole, 811: First opening, 812: Rear end, 82: Second hole, 821: Second opening, 83: Third hole, 831: Opening, 832: Opening, 91: Tip tool, 101, 101A: Hammer drill, 411: Driven gear, 414: Bearing, 800: Change lever, A1: Driving shaft, A2: Rotating shaft, A3: Rotating shaft, G: Gap, G1: First gap, G2: Second gap

Claims

1. A power tool, comprising: a rotary shaft that is rotationally driven by a motor, the rotary shaft having a first end portion located on a first direction side in the axial direction of the rotary shaft and a second end portion located on a second direction side opposite to the first direction side; a housing that houses the rotary shaft and into which a lubricant is introduced, the housing being configured to store the lubricant on the first direction side of the first end portion; The rotary shaft: has a first opening at the first end portion of the rotary shaft, and a first hole extending in the axial direction of the rotary shaft; a second hole that communicates with the first hole on the second direction side of the first opening, extends in a direction intersecting the axis of the rotary shaft, and has a second opening on the outer peripheral surface of the rotary shaft; a spiral portion is provided in the first hole to introduce the lubricant from the first opening by the spiral shape of the rotation of the rotary shaft and move the lubricant in the first hole to the second direction side; The spiral portion is formed as a separate member from the rotary shaft, inserted into the first hole, and fixed to the housing.

2. The power tool according to claim 1, further comprising: a holder that can fix the spiral portion to the housing.

3. The power tool according to claim 1 or claim 2, wherein: the tip of the spiral portion protrudes from the first opening of the rotary shaft to the first direction side.

4. The power tool according to any one of claims 1 to 3, wherein: the power tool is a percussion tool configured to perform at least a percussion operation; the power tool further comprises a final output shaft that detachably holds a tip tool and extends parallel to the rotary shaft, and a drive mechanism; The drive mechanism: includes the rotary shaft, a rotating body provided on the rotary shaft and rotatable integrally with the rotary shaft, and a swinging body configured to swing in the axial direction of the rotary shaft by the rotation of the rotating body, and the swinging body is configured to linearly drive the tip tool along the axis of the final output shaft when the swinging body swings; the second opening is provided inside the rotating body.

5. A power tool, comprising: A rotating shaft that is rotationally driven by a motor, the rotating shaft having a first end portion located on the first direction side in the axial direction of the rotating shaft and a second end portion located on the second direction side opposite to the first direction side. A housing that houses the rotating shaft and into which a lubricant is introduced, the housing being configured to be able to store the lubricant on the first direction side of the first end portion. The rotating shaft is provided with a first opening at the first end portion of the rotating shaft, and a first hole extending in the axial direction of the rotating shaft. A second hole that communicates with the first hole on the second direction side of the first opening, extends in a direction intersecting the axis of the rotating shaft, and has a second opening on the outer peripheral surface of the rotating shaft. In the first hole, a spiral portion is provided that introduces the lubricant from the first opening by the spiral shape of the rotation of the rotating shaft and moves the lubricant in the first hole to the second direction side. The power tool is a percussion tool configured to be able to perform at least a percussion operation. The power tool further includes a final output shaft that detachably holds a tip tool and extends parallel to the rotating shaft, and a drive mechanism. The drive mechanism is configured to include the rotating shaft, a rotating body provided on the rotating shaft and rotatable integrally with the rotating shaft, and a swinging body configured to swing in the axial direction of the rotating shaft by the rotation of the rotating body. When the swinging body swings, the tip tool is driven linearly along the axis of the final output shaft. The second opening is provided inside the rotating body. A power tool.

6. The power tool according to claim 5, comprising a switching member that can switch between a state in which the rotating body rotates integrally with the rotating shaft and the power tool can perform the percussion operation, and a state in which the rotating body does not rotate integrally with the rotating shaft and the power tool cannot perform the percussion operation. A power tool.

7. The power tool according to claim 5 or claim 6, wherein the rotating body includes at least one third hole that extends in a direction intersecting the axis of the rotating shaft and has openings on the inner peripheral surface and the outer peripheral surface of the rotating body, respectively. A power tool.

8. The power tool according to claim 7, wherein the at least one third hole includes two third holes. A power tool, wherein the two third holes are provided so as to face each other with the rotary shaft therebetween. **Claim 9**: A power tool according to any one of claims 5 to 8, A power tool, wherein the spiral portion is provided in the first hole and configured to be rotatable integrally with the rotary shaft. **Claim 10** A power tool according to any one of claims 1 to 9, A power tool, wherein the lubricant is grease.

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