Power tool

Abstract

A power tool is provided. The power tool has a rotary shaft that is rotationally driven by a motor, and a housing that houses the rotary shaft. The rotary shaft has a first end portion on a first direction side in an axial direction of the rotary shaft, and a second end portion on a second direction side. The housing houses the rotary shaft, and is configured to be able to store a lubricant on the first direction side of the first end portion of the rotary shaft. The rotary shaft has a first hole and a second hole. The first hole has a first opening at the first end portion of the rotary shaft, and extends in a front-rear direction. The second hole communicates with the first hole, and extends in a direction intersecting an axis of the rotary shaft. The second hole has a second opening at an outer peripheral surface of the rotary shaft. A spiral portion is provided in the first hole. Accordingly, a technique that suppresses wear of components in the power tool can be provided.

Description

Technical Field

[0001] This invention relates to a power tool. Background Technology

[0002] In power tools, lubricant is sometimes introduced into the housing to suppress wear on components housed within it. Patent Document 1 describes a hammer drill with a lubricant reservoir formed in the area between the drive shaft and the bearing structure. In this hammer drill, the reservoir is sealed by a sealing member, thereby preventing lubricant leakage. This achieves lubrication between the drive shaft and the bearing structure, suppressing wear.

[0003] [Existing technical documents]

[0004] [Patent Literature]

[0005] Patent Document 1: European Patent Application Publication No. 1861631 Summary of the Invention

[0006] [The technical problem that the invention aims to solve]

[0007] Without relying on the technology of Patent Document 1, a technology is sought for a power tool that introduces lubricant into the housing to suppress the wear of components inside the housing.

[0008] [Technical solutions used to solve technical problems]

[0009] The present invention can be achieved through the following technical solutions.

[0010] According to a technical solution of the present invention, a power tool is provided. The power tool has a rotating shaft and a housing. The rotating shaft has a first end located on a first direction side in the axial direction of the rotating shaft and a second end located on a second direction side opposite to the first direction side. The rotating shaft is configured to be driven by a motor for rotation. The housing houses the rotating shaft. A lubricant is introduced into the interior of the housing. The housing is configured to accumulate the lubricant on the first direction side of the first end of the rotating shaft. In other words, the housing is configured to accumulate the lubricant in a space region within the interior space of the housing where the first end of the rotating shaft is disposed. Alternatively, the housing is configured to accumulate the lubricant between the first end of the rotating shaft and a wall of the housing disposed on the first direction side of the first end. The rotating shaft has a first hole and a second hole. The first hole is configured to have a first opening at the first end of the rotating shaft and extend along the axial direction of the rotating shaft. The second hole communicates with the first hole at a position closer to the second direction side than the first opening. The second hole is configured to extend along a direction intersecting the axis of the rotation shaft, and has a second opening on the outer circumferential surface of the rotation shaft. A spiral portion is provided within the first hole.

[0011] According to this technical solution, when a user operates a power tool with the first end of the rotating shaft facing vertically downward or nearly vertically downward, the lubricant inside the housing can move within the housing due to gravity and accumulate on the first direction side of the first end of the rotating shaft. Since the rotating shaft has a first hole with a first opening at the first end and extending along the axial direction of the rotating shaft, and a helical portion is provided within the first hole, the accumulated lubricant can be introduced through the first opening using the rotation of the rotating shaft and the helical shape of the helical portion, and moved within the first hole towards the second direction side (vertically upward or nearly vertically upward). Furthermore, the rotating shaft has a second hole communicating with the first hole, extending in a direction intersecting the axis of the rotating shaft, and having a second opening on the outer circumferential surface of the rotating shaft. Therefore, the lubricant in the first hole can be discharged from the second opening of the second hole. Thus, during operation of the power tool, lubricant can be distributed throughout the rotating shaft and its surroundings. As a result, wear on the components constituting the power tool can be suppressed. Attached Figure Description

[0012] Figure 1 This is an image of a hammer drill.

[0013] Figure 2 It is a partial sectional view of a hammer drill, and is a diagram used to illustrate the internal structure of the hammer drill.

[0014] Figure 3 yes Figure 2The diagram shows a magnified view of the area near the axis of rotation and the rotating body, and is a diagram showing the state in which an impact action can be performed in a hammer drill.

[0015] Figure 4 Is with Figure 3 The corresponding diagram shows the state in which impact actions cannot be performed during hammer drilling.

[0016] Figure 5 It is a perspective view of the internal mechanism within the lubricant containment section, and an exploded perspective view of the retaining member and the spiral component.

[0017] Figure 6 Is with Figure 2 The corresponding enlarged view of the rotation axis and the vicinity of the rotating body is a diagram showing a hammer drill with a helical component fixed to the rotation axis.

[0018] [Explanation of reference numerals in the attached figures]

[0019] 2: Motor; 5: Drive mechanism; 10: Main housing; 131: Cylindrical section; 14: Inner housing; 141: Sealing ring; 143: Front wall; 144: Peripheral wall; 145: Rear wall; 16: Lubricant receiving part; 161: Front wall; 17: Handle; 171: Trigger; 179: Power cord; 31: Spindle; 32: Tool holder; 33: Cylinder; 40: Rotating shaft; 41: Front end; 42: Rear end; 45: Groove; 51: Motion conversion mechanism; 53: Rotating body; 531: External gear; 54: Oscillating body; 541: Rolling body; 55: Piston; 57: Impact structure element; 58: Hammer; 59: Bolt; 61: Clutch cam cam); 611: Internal gear; 71, 71A: Helical component; 711: Shaft; 712, 712A: Top end; 713, 713A: Rear end; 714: Bending part; 75: Retaining member; 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: Top tool; 101, 101A: Hammer drill; 411: Driven gear; 414: Bearing; 800: Change lever; A1: Drive axis; A2: Rotation axis; A3: Rotation axis; G: Clearance; G1: First clearance; G2: Second clearance. Detailed Implementation

[0020] The following describes in detail representative and non-limiting examples of the invention with reference to the accompanying drawings. This detailed description is merely intended to demonstrate to those skilled in the art the preferred embodiments for carrying out the invention, and is not intended to limit the scope of the invention. Furthermore, in order to provide further improved power tools, methods of manufacturing them, and methods of use, the additional technical features and solutions disclosed below may be used alone or in combination with other technical features or solutions.

[0021] Furthermore, the combinations of technical features or processes disclosed in the following detailed description are not essential for implementing the invention in the broadest sense, but are merely descriptions for illustrating representative specific examples of the invention. Moreover, when providing additional and useful embodiments of the invention, it is not necessary to combine the various technical features of the above and below representative examples, as well as the various technical features recited in the independent and dependent claims, in the order described herein or in the enumerated examples.

[0022] All technical features described in this specification and / or claims that differ in structure from those described in the embodiments and / or claims are disclosed separately and independently as a disclosure of the original application and as a limitation on the specific matters claimed. Furthermore, the descriptions of all numerical ranges and groups or categories, as a disclosure of the original application and as a limitation on the specific matters claimed, indicate the disclosure of intermediate configurations.

[0023] In one embodiment of the invention, the helical portion may be formed separately relative to the rotation axis. The helical portion may be inserted into the first hole and fixed to the housing.

[0024] According to the above embodiment, the structure in which the helical part is inserted into the first hole and fixed to the housing (i.e., the helical part does not rotate integrally with the rotating shaft) allows lubricant accumulated at the first end of the rotating shaft in the first direction to be introduced from the first opening into the first hole and moved towards the rear of the first hole, thereby being discharged from the second opening of the second hole. Therefore, during operation using a power tool, lubricant can be distributed throughout the rotating shaft and its surroundings.

[0025] Based on, or instead of, the above-described embodiments, the power tool may have a retaining member. The retaining member may be configured to secure the helical portion to the housing.

[0026] According to the above embodiment, the helical portion can be stably fixed to the housing. Furthermore, during operation using a power tool, changes in the configuration of the helical portion relative to the housing and the configuration of the helical portion relative to the rotation axis can be prevented.

[0027] Based on or instead of the above embodiments, the spiral portion may be configured to be disposed within the first hole and be able to rotate integrally with the rotating shaft.

[0028] According to the above embodiment, by means of a structure in which a helical portion is provided in the first hole and can rotate integrally with the rotating shaft, lubricant accumulated at the first end of the rotating shaft in the first direction can be introduced from the first opening into the first hole and moved towards the second direction side of the first hole, thereby being discharged from the second opening of the second hole. Therefore, during operation using a power tool, lubricant can be distributed throughout the rotating shaft and its surroundings.

[0029] Based on or instead of the above embodiments, the top end of the spiral portion may protrude from the first opening of the rotating shaft toward the first direction side.

[0030] According to the above embodiment, the tip of the helical portion protrudes from the first opening of the rotating shaft toward the first direction side, that is, into the space within the housing where lubricant can accumulate. Therefore, the tip of the helical portion can function as a guide for introducing lubricant into the first hole. Thus, lubricant can be distributed on and around the rotating shaft earlier after the start of operation with the power tool, thereby further suppressing wear on the components constituting the power tool.

[0031] Based on, or instead of, the above-described embodiments, the power tool may be an impact tool configured to at least perform an impact action. The power tool may have a final output shaft and a drive mechanism. The final output shaft may be configured to detachably hold the tip tool and extend parallel to the rotation axis. The drive mechanism may include the rotation axis, a rotating body, and a oscillating body. The rotating body may be disposed on the rotation axis and configured to rotate integrally with the rotation axis. The oscillating body may be configured to oscillate axially along the rotation axis by the rotation of the rotating body. The drive mechanism may be configured to drive the tip tool linearly along the axis of the final output shaft by the oscillation of the oscillating body. The second opening may be located inside the rotating body.

[0032] According to the above embodiment, when the user performs an impact operation by impacting the workpiece with the tip of the impact tool facing vertically downward or nearly vertically downward, lubricant is supplied between the rotating shaft and the rotating body, thus effectively suppressing wear on the rotating shaft and the rotating body. Furthermore, the rotating shaft, as part of the drive mechanism, can function as a lubricant supplier between the rotating shaft and the rotating body, and around the rotating shaft. Therefore, it is possible to suppress the structural complexity of the impact tool and the increase in the number of components that would enlarge the outer profile of the impact tool due to the need to circulate lubricant to achieve component circulation.

[0033] Based on or instead of the above embodiments, the power tool may have a switching component. The switching component may be configured to switch between a state in which the rotating body rotates integrally with the rotating shaft, enabling the power tool to perform the impact action, and a state in which the rotating body does not rotate integrally with the rotating shaft, preventing the power tool from performing the impact action.

[0034] According to the above embodiment, since the lubricant is discharged from the second opening to the inside of the rotating body, a power tool can be provided that can suppress wear between the rotating body and the rotating shaft, and can switch between a state in which impact action can be performed and a state in which impact action cannot be performed.

[0035] Based on, or instead of, the above-described embodiments, the rotating body may have at least one third hole. The third hole may be configured to extend along a direction intersecting the axis of rotation and have openings on both the inner and outer circumferential surfaces of the rotating body.

[0036] According to the above 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 on the outer peripheral surface of the rotating body to the periphery of the rotating body (the interior of the housing). Therefore, during machining operations in which the first end of the rotating shaft faces downward or nearly downward, the lubricant can be distributed between the rotating shaft and the rotating body and around the rotating body. As a result, wear of the components constituting the power tool due to machining operations can be further suppressed. In addition, the rotating shaft and rotating body of the power tool can be used to effectively suppress wear of the components constituting the power tool.

[0037] Based on, or instead of, the above-described embodiments, the at least one third hole may include two third holes. The two third holes may be positioned facing each other across the rotation axis. In other words, the two third holes may extend along a straight line intersecting the rotation axis.

[0038] According to the above embodiment, since the two third holes are set to face each other across the rotation axis, lubricant can be discharged from the rotating body, and imbalance of the rotating body can be suppressed. Therefore, the rotating body can rotate stably on the rotation axis.

[0039] Based on or instead of the above embodiments, the lubricant may be a lubricating grease.

[0040] According to the above embodiments, since the grease has high viscosity, it is possible to suppress excessive requirements on the precision of the sealing mechanism used to prevent lubricant leakage from the housing in power tools.

[0041] The following is for reference Figures 1 to 5 The following describes a power tool according to one embodiment. In this embodiment, a hammer drill 101 is exemplified as a power tool. The hammer drill 101 is a portable power tool used for chiseling, drilling, and other machining operations, and is configured to perform an action that drives the tip tool 91 in a straight line along a predetermined drive axis A1 (hereinafter referred to as an impact action) and an action that drives the tip tool 91 to rotate about the drive axis A1 (hereinafter referred to as a rotation action).

[0042] First, a brief description of the general structure of the hammer drill 101 will be given. For example... Figure 1 As shown, the outer contour of the hammer drill 101 is mainly formed by the main body housing 10 and the handle 17 connected to the main body housing 10.

[0043] The main body shell 10 is a hollow body, also known as the tool body or outer contour shell. For example... Figure 2 As shown, the main housing 10 mainly houses the spindle 31, the motor 2, and the drive mechanism 5.

[0044] The spindle 31 is an elongated cylindrical component. A tool holder 32 is provided at one end of the spindle 31. The tool holder 32 is configured to detachably hold the tip tool 91. The long 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 of the main body housing 10 in the extending direction of the drive axis A1.

[0045] like Figure 1As shown, the handle 17 is an elongated, hollow body held by the user. One axial end of the handle 17 is connected to the other end of the main housing 10 (the end opposite to the end where the tool holder 32 is located). The handle 17 extends from the other end of the main housing 10 in a direction intersecting (more specifically, approximately orthogonal) the drive axis A1. A power cord 179, which can be connected to an external AC power source, 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 becomes active in response to the pressing of the trigger 171.

[0046] When the trigger 171 is pressed to turn the switch on, the motor 2 is energized, and the drive mechanism 5 is driven. In the hammer drill 101 of this embodiment, impact and / or rotation actions are performed by driving the drive mechanism 5.

[0047] The detailed structure of the hammer drill 101 will now be described. For ease of explanation, the extension direction of the drive shaft A1 will be defined as the front-rear direction of the hammer drill 101. In the front-rear direction, the end side where the tool holder 32 is disposed will be defined as the front side of the hammer drill 101, and the opposite side (the side connected to the handle 17) will be defined as the rear side. Furthermore, the direction orthogonal to the drive shaft A1 and corresponding to the axial direction of the handle 17 will be defined as the vertical direction of the hammer drill 101. In the vertical direction, the side of the main housing 10 where the handle 17 is connected will be defined as the upper side, and the protruding end side of the handle 17 will be defined as the lower side. Additionally, the direction orthogonal to both the front-rear and vertical directions will be defined as the left-right direction.

[0048] like Figure 1 and Figure 2 As shown, the front end of the main body housing 10 is formed in a cylindrical shape. This cylindrical portion is also referred to as the cylindrical portion 131. The portion of the main body housing 10 other than the cylindrical portion 131 is formed in a generally rectangular box shape.

[0049] like Figure 2 As shown, a hollow inner shell 14 is disposed inside the main body shell 10. The inner shell 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 various bearings. The rear wall 145 is configured to intersect with the drive shaft A1. The inner shell 14 is embedded into the inner periphery of the main body shell 10 and is fixedly held in the main body shell 10.

[0050] A sealing ring 141 is sandwiched between the outer periphery of the front wall 143 of the inner housing 14 and the inner periphery of the main housing 10. Lubricant is introduced into the portion of the main housing 10 forward of the sealing ring 141 and into the inner housing 14. This portion of the main housing 10 forward of the sealing ring 141 and the inner housing 14 are also referred to as the lubricant receiving portion 16. The sealing ring 141 prevents lubricant from leaking out of the lubricant receiving portion 16. The motor 2 is mainly housed in the region on the rear side of the inner housing 14 (rear wall 145). The spindle 31 and the drive mechanism 5 are mainly housed in the region on the front side of the rear wall 145 (lubricant receiving portion 16). Furthermore, most of the drive mechanism 5 and the rear end of the spindle 31 are housed within the inner housing 14. In this embodiment, a grease with a higher viscosity than oil is used as the lubricant.

[0051] The internal structure of the main body shell 10 will be described below. For example... Figure 2 As shown, the main housing 10 mainly houses the main shaft 31, motor 2, drive mechanism 5, and clutch cam 61.

[0052] The main shaft 31 is disposed within the lubricant receiving section 16 and extends in the front-to-back direction. The main shaft 31 is configured as an elongated, stepped cylindrical component. The main shaft 31 is supported by two bearings in a manner that allows it to rotate about the drive axis A1.

[0053] As described above, the front half of the spindle 31 constitutes a tool holder 32 for the detachable tip tool 91. The rear half of the spindle 31 constitutes a cylinder 33 that slidably holds the piston 55 (described later). In this embodiment, the spindle 31 is a single component integrally formed from the tool holder 32 and the cylinder 33. In another embodiment, the spindle 31 can be formed by connecting multiple components.

[0054] Motor 2 is housed within the rear portion of the inner housing 14 (rear wall 145) of the main housing 10. Although detailed illustrations are omitted, motor 2 includes a motor body and a motor shaft, wherein the motor body includes a stator and a rotor; the motor shaft extends from the rotor. The rotation axis A2 of the motor shaft extends parallel to (in the front-rear direction) the drive axis A1 at a position lower than the drive axis A1. In this embodiment, motor 2 is an AC motor driven by receiving power from an external power source via power line 179. In another embodiment, motor 2 may be a DC motor driven by receiving power from a battery pack. The front end of the motor shaft protrudes through the rear wall 145 into the inner housing 14.

[0055] like Figure 2As shown, the drive mechanism 5 includes a rotating shaft 40, a motion conversion mechanism 51, and an impact structure element 57. The drive mechanism 5 is configured to perform an action (impact action) that drives the tip tool 91 in a linear manner along the front-back direction.

[0056] The rotating shaft 40 extends in the front-to-back direction within the lubricant receiving portion 16. That is, the rotation axis A3 of the rotating shaft 40 extends parallel to the drive axis A1 and the rotation axis A2. The rotating shaft 40 is supported by two bearings in a manner rotatable about the rotation axis A3. Of these two bearings, the front bearing is held in the inner housing 14, and the rear bearing 414 is held in the rear wall 145. Figure 3 As shown, the front end 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 housing 10 (lubricant receiving section 16). Furthermore, when the front end of the hammer drill 101 faces downward or nearly downward, the space where the front end 41 is positioned is a space where lubricant in the internal space of the lubricant receiving section 16 easily accumulates due to gravity. A driven gear 411 is fixed to the rear end 42 of the rotating shaft 40. The driven gear 411 meshes with a pinion (not shown) fixed to the front end of the motor shaft, and the rotating shaft 40 rotates as the motor shaft rotates.

[0057] The motion conversion mechanism 51 is configured to convert the rotational motion of the rotating shaft 40 into linear motion and transmit it to the impact structure element 57. The motion conversion mechanism 51 includes a rotating body 53, a swinging body 54, and a piston 55.

[0058] like Figure 3 As shown, the rotating body 53 is disposed on the rotating shaft 40 (around the rotating shaft 40) in a manner that allows it to rotate selectively relative to the rotating shaft 40. External teeth 531 (clutch teeth) are provided on the outer periphery of the front end of the rotating body 53.

[0059] The oscillating body 54 is movably connected to the rotating body 53 via a rolling element 541 disposed on the outer periphery of the rotating body 53. The rotating body 53, rolling element 541, and oscillating body 54 are collectively referred to as a swashplate bearing. The oscillating body 54 oscillates in the back-and-forth direction as the rotating body 53 rotates. Figure 2 As shown, the piston 55 is formed into a bottomed cylindrical shape and is held in the cylinder 33 in a manner that allows it to move in the back-and-forth direction. The piston 55 is movably connected to the swing body 54 and reciprocates in the back-and-forth direction as the swing body 54 swings.

[0060] like Figure 2As shown, the impact structure element 57 is configured to impact the tip tool 91 in a linear motion, thereby driving the tip tool 91 linearly along the drive axis A1. The impact structure element 57 includes a hammer 58 and a striker 59. The hammer 58 is disposed within the piston 55 in a manner that allows it to slide in the front-rear direction. The striker 59 is disposed in front of the hammer 58. The space (air cavity) inside the piston 55 behind the hammer 58 functions as an air spring.

[0061] When the rotating body 53 rotates and the piston 55 moves forward along with the swinging body 54, the air in the air chamber is compressed and its internal pressure rises. The hammer 58, under the action of the air spring, is pushed forward at high speed and impacts the striker 59, thereby transferring kinetic energy to the end tool 91. Accordingly, the end tool 91 is linearly driven along the drive axis A1, thereby impacting the workpiece. On the other hand, when the piston 55 moves backward along with the swinging body 54, the air in the air chamber expands and its internal pressure decreases, thereby pulling the hammer 58 backward. In this way, the drive mechanism 5 can repeatedly perform impact actions.

[0062] 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. For example... Figure 3 As shown, the clutch cam 61 is mounted on the rotating shaft 40. The clutch cam 61 engages with the outer periphery of the rotating shaft 40 via a spline on the front side of the rotating body 53. The clutch cam 61 is substantially immobile circumferentially relative to the rotating shaft 40 but is movable along the extension direction (front-back direction) of the rotation axis A3. The clutch cam 61 is operable in a manner with a user-operable shift lever 800 (see reference). Figure 1 , 5 The clutch cam 61 moves along the rotary shaft 40 in the back-and-forth direction by operating the shift lever 800.

[0063] like Figure 3 As shown, when the clutch cam 61 is moved to the position where the internal teeth 611 of the clutch cam 61 engage with the external teeth 531 of the rotating body 53 (engaged position), the rotating body 53 rotates integrally with the rotating shaft 40. At this time, the oscillating body 54 oscillates due to the rotation of the rotating body 53, and the drive mechanism 5 performs an impact action. Additionally, as... Figure 4 As shown, when the clutch cam 61 is moved from the engaged position to the forward position (disengaged 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. Accordingly, the rotating body 53 cannot rotate integrally with the rotating shaft 40. At this time, the drive mechanism 5 does not perform an impact action. In this way, the clutch cam 61 switches between the state where the drive mechanism 5 can perform an impact action and the state where it cannot.

[0064] Furthermore, although detailed illustrations and explanations are omitted, a rotary transmission mechanism is additionally provided on the hammer drill 101 to transmit rotation from the motor 2 to the spindle 31. By operating the switching lever 800, the user can switch between a state where the rotation of the motor 2 is transmitted to the spindle 31 via the rotary transmission mechanism and a state where it is not transmitted to the spindle 31. When the rotation of the motor 2 is transmitted to the spindle 31, the tip tool 91 is driven to rotate. Additionally, the hammer drill 101 is configured to operate in any of the following modes: a rotation-impact mode capable of both rotational action based on the rotary transmission mechanism and impact action based on the drive mechanism 5; a rotation-only mode capable of only rotational action; and an impact-only mode capable of only impact action. These operating modes can be switched by operating the switching lever 800.

[0065] like Figures 3 to 5 As shown, the hammer drill 101 also includes: a first hole 81 and a second hole 82, which are disposed on the rotating shaft 40; a spiral component 71, which is inserted into the first hole 81; and a third hole 83, which is disposed on the rotating body 53. In the hammer drill 101, through these structures, proper lubrication of the components inside the lubricant receiving section 16 can be achieved.

[0066] like Figure 3 and Figure 4 As shown, the first hole 81 has a first opening 811 at the front end 41 of the rotating shaft 40 and extends in the front-rear direction. The axis of the first hole 81 is aligned with the rotation axis A3 of the rotating shaft 40. Furthermore, the first hole 81 does not penetrate the rotating shaft 40 in the front-rear direction, and the rear end 812 of the first hole 81 is located inside the rotating shaft 40.

[0067] The second hole 82 communicates with the first hole 81 at a position rearward of the first opening 811 and extends radially along the rotation axis 40. In this embodiment, the second hole 82 communicates with the first hole 81 near 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 rotation axis 40. The second opening 821 is provided inside the rotating body 53.

[0068] Furthermore, 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 this embodiment, the gap G includes a first gap G1 and a second gap G2. In this embodiment, a plurality of grooves 45 extending in the direction of the rotation axis A3 (front-back direction) are provided circumferentially on the outer peripheral surface of the rotating shaft 40. The grooves 45 extend from the position where the rotating body 53 is disposed to a position further forward than 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. In addition, the inner diameter of the rotating body 53 is formed slightly larger in a portion including the part of the rotating body 53 facing the second opening 821. The second gap G2 can be defined by the inner peripheral surface of the portion of the rotating body 53 where the inner diameter is formed 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 in the second gap G2.

[0069] The helical component 71 has a helical shaft 711. The shaft 711 is disposed within the first hole 81 and extends in the front-rear direction. In this embodiment, the helical component 71 is formed separately relative to the rotating shaft 40. The helical component 71 can be formed, for example, by sheet metal processing. Alternatively, a compression spring can be used as the helical component 71. The helical shape of the shaft 711 is formed at intervals such that when the rotating shaft 40 is rotated by supplying lubricant from the first opening 811 to the first hole 81, the lubricant can move rearward along the shaft 711. The first hole 81 of the rotating shaft 40 (defining the inner peripheral wall of the rotating shaft 40 with the first hole 81) and the helical component 71 (shaft 711) constitute a so-called Archimedes screw.

[0070] In this embodiment, the top end portion 712 of the spiral member 71 (shaft portion 711) protrudes forward from the first opening 811. The top 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, which is located forward of the front end portion 41. Figure 5 As shown, the top end 712 of the spiral member 71 has a curved portion 714 that is hook-shaped.

[0071] In this embodiment, a retainer 75 for fixing the spiral component 71 to the lubricant receiving portion 16 is arranged around the front end portion 41 of the rotation axis 40. For example... Figure 5As shown, the retainer 75 has a locking groove 755 and a fixing portion 753, wherein the locking groove 755 allows the bent portion 714 of the helical member 71 to be locked therein; and the fixing portion 753 can be fixed to the front wall 143 of the inner housing 14. The retainer 75 is configured such that, with the fixing portion 753 fixed to the front wall 143, the axis of the insertion hole 751 provided at the front end of the retainer 75 coincides with the axis of the first hole 81 (the rotation axis A3 of the rotation shaft 40). By inserting the rear end portion 713 of the shaft portion 711 into the insertion hole 751 of the retainer 75, the bent portion 714 is locked in the locking groove 755, and the helical member 71 is fixed to the inner housing 14 by the retainer 75. Accordingly, the helical member 71 does not rotate with the rotation shaft 40.

[0072] The rotating body 53 has a third hole 83. The third hole 83 has openings 831 and 832 on the inner and outer peripheral surfaces of the rotating body 53, respectively, and extends along a direction intersecting the axis of the rotating body 53 (the rotation axis A3 of the rotation shaft 40). In this embodiment, the rotating body 53 has two third holes 83. The two third holes 83 face each other across the rotation shaft 40. 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 a 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 track of the rolling element 541 is not disposed.

[0073] The following will describe the method of lubrication of the components constituting the hammer drill 101 and the effect of the hammer drill 101 in this embodiment.

[0074] For example, during floor chiseling or drilling operations, when the tip tool 91 of the hammer drill 101 (i.e., the front end 41 of the rotating shaft 40) is facing vertically downward or nearly vertically downward, the lubricant in the lubricant receiving section 16 can move to the front part of the lubricant receiving section 16 (the front part of the front end 41 of the rotating shaft 40) due to gravity and remain there. When the upper surface (surface) of the lubricant reaches the front end 41 (first opening 811) of the rotating shaft 40, the lubricant moves backward in the first hole 81 according to the principle of the Archimedes screw. The lubricant that moves backward in the first hole 81 is discharged from the second opening 821 of the second hole 82 and spreads across the rotating shaft 40. More specifically, the lubricant is discharged from the second opening 821 into the second gap G2, moves in the first gap G1 (transmitted in the groove 45), and spreads across the rotating shaft 40. Therefore, wear on components on the rotating shaft 40, such as the rotating body 53, clutch cam 61, and bearings of the rotating shaft 40, can be suppressed. Furthermore, the lubricant can be supplied to the area surrounding the rotating shaft 40 as the rotating shaft 40 rotates. Accordingly, wear on components on the rotating shaft 40 and the rotating shaft 40, as well as wear on components surrounding the rotating shaft 40, can be suppressed, thereby extending the service life of these components.

[0075] Furthermore, lubricant discharged from the second opening 821 into the second gap G2 flows into the third hole 83 from the opening 831 of the rotating body 53, and is discharged into the lubricant receiving portion 16 from the opening 832. At this time, due to the rotation of the rotating body 53, the lubricant is distributed from the opening 832 into the lubricant receiving portion 16. Therefore, wear on the rotating body 53 and its components, such as the rolling body 541 and the oscillating body 54, as well as wear on other components in the lubricant receiving portion 16, such as the piston 55, can be suppressed, thereby extending the service life of these components.

[0076] Furthermore, the drive mechanism 5 of the hammer drill 101 is configured to convert the rotation of the rotating shaft 40 into linear motion and transmit it to the tip tool 91 held on the spindle 31 to perform an impact action. That is, the rotating shaft 40, as part of the drive mechanism 5, can function to circulate the lubricant within the lubricant receiving section 16. Therefore, it is possible to suppress the structural complexity of the hammer drill 101 caused by the circulation of components for the purpose of lubricant circulation, and to suppress the increase in the number of components constituting the hammer drill 101, which would enlarge the external profile of the hammer drill 101.

[0077] In this embodiment, the tip 712 of the spiral member 71 protrudes forward from the first opening 811. Therefore, the tip 712 of the spiral member 71 can function as a guide to introduce lubricant into the first hole 81. Thus, in the hammer drill 101 of this embodiment, lubricant can be distributed on and around the rotating shaft 40 earlier after the start of operation, thereby further suppressing wear on the components constituting the hammer drill 101.

[0078] Lubricant discharged from the second opening 821 of the second hole 82 and 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 rotating shaft 40. Furthermore, wear between the internal teeth 611 of the clutch cam 61 and the external teeth 531 of the rotating body 53 can be suppressed. Therefore, the engaged and disengaged states of the clutch cam 61 and the rotating body 53 can be smoothly switched, thereby allowing smooth switching between the impact-capable mode (rotary impact mode, impact-only mode) and the non-impact-capable mode (rotary mode) in the hammer drill 101.

[0079] Furthermore, two third holes 83 are provided on the rotating body 53, and these two third holes 83 are arranged facing each other across the rotating shaft 40. Therefore, lubricant can be discharged from the rotating body 53, and imbalance of the rotating body 53 can be suppressed. Thus, the rotating body 53 can rotate stably on the rotating shaft 40.

[0080] Furthermore, the helical component 71 is constructed separately from the rotating body 53 and is inserted into the first hole 81. Therefore, for example, compared to providing a helical groove on the inner wall of the first hole 81, it is easier to manufacture a structure (Archimedean screw) for moving the lubricant backward into the first hole 81. In addition, the helical component 71 is fixed to the lubricant receiving portion 16 (inner housing 14) by the retainer 75, thus stabilizing the fixed state of the helical component 71 relative to the lubricant receiving portion 16.

[0081] In this embodiment, grease is used as the lubricant. Generally, grease has a high viscosity. Therefore, by using a simple structure such as sandwiching a sealing ring 141 between the outer periphery of the inner housing 14 and the inner periphery of the main housing 10, leakage of lubricant from the lubricant receiving part 16 can be prevented.

[0082] The correspondence between the structural elements of the above embodiments and the structural elements of the present invention is shown below. However, the structural elements of the embodiments are merely examples and do not limit the structural elements of the present invention.

[0083] Hammer drill 101 is an example of a "power tool" or "impact tool".

[0084] Motor 2 is an example of a "motor".

[0085] Rotation axis 40 is an example of a "rotation axis".

[0086] The axis of rotation A3 of the rotation axis 40 is an example of the "axis of rotation axis".

[0087] The extension direction (front-back direction) of the rotation axis A3 is an example of the "axial direction of the rotation axis", and the front side and the back side are examples of the "first direction side" and "second direction side", respectively.

[0088] The front end 41 and rear end 42 of the rotating shaft 40 are examples of "first end" and "second end", respectively.

[0089] The lubricant receiving section 16 (main body housing 10, inner housing 14) is an example of a "housing".

[0090] The first opening 811 is an example of the "first opening".

[0091] Hole 1, number 81, is an example of "hole 1".

[0092] The second opening 821 is an example of the "second opening".

[0093] Hole 2, number 82, is an example of "hole 2".

[0094] The radial direction of the rotation axis 40 is an example of "the direction that intersects the axis of rotation".

[0095] Spiral component 71 and shaft portion 711 are examples of "spiral components".

[0096] Retainer 75 is an example of a "retainer".

[0097] The apex 712 is an example of a "apex".

[0098] Top tool 91 is an example of "top tool".

[0099] Spindle 31 is an example of a "final output axis".

[0100] Drive axis A1 is an example of the "axis of the final output axis".

[0101] Drive mechanism 5 is an example of a "drive mechanism".

[0102] Rotational solid 53 is an example of a "rotational solid".

[0103] Oscillating body 54 is an example of an "oscillating body".

[0104] Clutch cam 61 is an example of a "switching component".

[0105] Hole 3 (83), opening 831, and opening 832 are examples of "hole 3" and "opening", respectively.

[0106] Furthermore, the above embodiments are merely examples, and the power tools involved in this invention are not limited to the hammer drill 101 exemplified in the above embodiments. For example, non-limiting modifications as illustrated below can be added. In addition, at least one of these modifications can be used in combination with at least a portion of the structure (technical feature) of the hammer drill 101 and at least one of the structure (technical feature) described in the claims.

[0107] The mechanism described in the above embodiments, which provides a first hole 81 and a second hole 82 on the rotating shaft 40 and arranges a spiral part on the first hole 81 to circulate lubricant, is not limited to the hammer drill 101, but can also be applied to other power tools that have a rotating shaft that is rotated by a motor.

[0108] The first hole 81 is not limited to the rotating shaft 40 of the above embodiment, but can also be provided on a shaft that rotates by the power of the motor 2. For example, the first hole 81 and the helical part can be provided on an extension of the motor shaft or on the final output shaft that outputs the rotational power of the motor 2. In this case, the extension of the motor shaft or the final output shaft can function as a rotating shaft that circulates the lubricant.

[0109] The rear end 812 of the first hole 81 may not be located within the rotating shaft 40, and the first hole 81 may extend through the rotating shaft 40 along the rotation axis A3. Furthermore, the second hole 82 only needs to communicate with the first hole 81 at a position rearward of the first opening 811, and may not communicate with the rear end 812 of the first hole 81. Moreover, at least one second hole 82 needs to be provided on the rotating shaft 40, and the rotating shaft 40 may have two or more second holes 82. The second hole 82 may not extend radially along the rotating shaft 40, but may extend in a direction intersecting the rotation axis A3 of the rotating shaft 40. According to these methods, the lubricant discharged from the second opening 821 of the first hole 81 can be distributed throughout the rotating shaft 40. Furthermore, by rotating the rotating shaft 40, the lubricant on the rotating shaft 40 can be distributed around the rotating shaft 40. Furthermore, as described 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 lubricant from remaining in the first hole 81 or from being discharged from any part other than the second opening 821. Therefore, it has the advantage that lubricant flowing into the first hole 81 from the first opening 811 can be supplied to the parts requiring lubrication without any waste.

[0110] The rotating body 53 may also lack the third hole 83. In this manner, the lubricant discharged from the second opening 821 of the first hole 81 can be distributed throughout the rotating shaft 40. Furthermore, by rotating the rotating shaft 40, the lubricant on the rotating shaft 40 can be distributed around the rotating shaft 40.

[0111] When a third hole 83 is provided on the rotating body 53, the number of the third hole 83 can be one or more. The position of the third hole 83 (opening 832) and the direction of extension of the third hole 83 can also be changed appropriately.

[0112] The spiral component can rotate integrally with the rotating shaft 40. For example... Figure 6 As shown, it can also be configured such that the shaft portion 711 of the spiral 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 portion 812 of the first hole 81, so that the spiral member 71A rotates integrally with the rotating shaft 40. Furthermore, in this case, the top end portion 712A of the spiral member 71A may not have a bend 714, and the hammer drill 101A may not have a retainer 75. In this configuration, even if the upper surface (interface) of the lubricant that has moved to the front of the lubricant receiving portion 16 has not reached the first opening 811, as long as it reaches the top end portion 712A of the spiral member 71A, the lubricant can be introduced into the first hole 81 through the top end portion 712A via the rotation of the spiral member 71A (top end portion 712A).

[0113] The helical portion of the rotating shaft 40 may not be a separate component. For example, a helical groove may be provided on the inner wall of the rotating shaft 40, so that the helical portion rotates integrally with the rotating shaft 40. Even in this manner, the lubricant can move to the rear of the first hole 81 and be discharged from the second opening 821 of the second hole 82, thus enabling lubrication of the components constituting the hammer drill 101.

[0114] The configuration of the rotating shaft 40, the motor 2 (motor shaft), and the final output shaft (main shaft 31) is not limited to the configuration described in the above embodiment. For example, the rotation axis A3 of the rotating shaft 40 may intersect with the drive axis A1 and the rotation axis A2 of the motor shaft. Even in this manner, if the user operates the power tool with the front end 41 of the rotating shaft 40 facing vertically downward or nearly vertically downward, the lubricant is also transmitted in the spiral portion provided in the first hole 81 and moves within the first hole 81, and is discharged onto the rotating shaft 40 from the second opening 821, thus suppressing wear on the components on and around the rotating shaft 40.

[0115] Furthermore, in view of the present invention and the spirit of the above embodiments, the following methods are constructed. At least one of the following methods can be used in combination with at least one of the above embodiments and their variations, and the structures (features) described in each claim.

[0116] [Method 1]

[0117] The switching component is configured as follows:

[0118] It is capable of rotating integrally with the rotating shaft and is configured on the rotating shaft in a manner that allows it to move along the rotating shaft in the front-rear direction.

[0119] In the front-back direction, the rotating shaft rotates together with the rotating body by moving to an engaged position that engages with the rotating body, and the rotating shaft does not rotate together with the rotating body by moving to a position where the engagement with the rotating body is released.

[0120] [Method 2]

[0121] The rotating body is disposed on the rotating shaft with a gap between it and the rotating shaft.

[0122] The second hole faces the gap opening.

[0123] [Method 3]

[0124] The gap includes a first gap, which is formed by the inner circumferential surface of the larger portion of the inner diameter of the rotating body and the outer circumferential surface of the rotating shaft.

[0125] [Method 4]

[0126] The gap includes a second gap, which is defined by a groove provided on the outer circumferential surface of the rotating shaft and the inner circumferential surface of the rotating body.

[0127] [Method 5]

[0128] The second gap is larger than the first gap.

Claims

1. A power tool, characterized in that, It has a rotating shaft and a housing, wherein, The rotating shaft is driven to rotate by a motor and has a first end located on a first direction side in the axial direction of the rotating shaft and a second end located on a second direction side opposite to the first direction side; The housing houses the rotating shaft and introduces lubricant inside, the housing being configured to accumulate the lubricant on the first direction side of the first end. The rotating shaft has a first hole and a second hole, wherein, The first hole has a first opening at the first end of the rotating shaft and extends along the axial direction of the rotating shaft; The second hole communicates with the first hole at a position closer to the first opening in the second direction, and extends in a direction intersecting the axis of the rotation shaft. It has a second opening on the outer circumferential surface of the rotation shaft. A spiral portion is provided inside the first hole. The power tool is an impact tool configured to at least perform impact actions. The power tool also has a final output shaft and a drive mechanism, wherein the final output shaft detachably holds the tip tool and extends parallel to the rotation axis. The drive mechanism includes the rotating shaft, a rotating body, and a swinging body, and is configured to drive the tip tool linearly along the axis of the final output shaft by swinging the swinging body. The rotating body is mounted on the rotating shaft and is capable of rotating integrally with the rotating shaft; the swinging body is configured to swing axially along the rotating shaft by the rotation of the rotating body. The second opening is located on the inside of the rotating body.

2. The power tool according to claim 1, characterized in that, The spiral portion is formed separately relative to the rotation axis and inserted into the first hole, and is fixed to the housing.

3. The power tool according to claim 2, characterized in that, It has a retainer that allows the spiral portion to be secured to the housing.

4. The power tool according to claim 1, characterized in that, The spiral portion is disposed within the first hole and is configured to rotate integrally with the rotating shaft.

5. The power tool according to any one of claims 1 to 4, characterized in that, The tip of the spiral portion protrudes from the first opening of the rotating shaft toward the first direction side.

6. The power tool according to claim 1, characterized in that, It has a switching component that can switch between two states: a state in which the rotating body rotates integrally with the rotating shaft, enabling the power tool to perform the impact action, and a state in which the rotating body does not rotate integrally with the rotating shaft, preventing the power tool from performing the impact action.

7. The power tool according to claim 1, characterized in that, The rotating body has at least one third hole extending along a direction intersecting the axis of rotation, and has openings on the inner and outer circumferential surfaces of the rotating body, respectively.

8. The power tool according to claim 6, characterized in that, The rotating body has at least one third hole extending along a direction intersecting the axis of rotation, and has openings on the inner and outer circumferential surfaces of the rotating body, respectively.

9. The power tool according to claim 7, characterized in that, The at least one third hole includes two third holes. The two third holes are positioned facing each other across the rotation axis.

10. The power tool according to any one of claims 1 to 4, characterized in that, The lubricant is a grease.

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