HAND TOOL MACHINE, ESPECIALLY IMPACT SCREWDRIVERS

Description

[0001] The invention relates to a hand-held power tool, in particular an impact wrench, having a drive train for driving a tool holder provided for receiving a tool, in particular a screwing tool, about a rotational axis according to the preamble of claim 1.

[0002] Such a hand-held power tool is described in US 3 175 660 A.

[0003] Another hand-held power tool in the form of an impact wrench is mentioned, for example, in DE 10 2007 003 037 A1. In practice, it has been found that with such an impact wrench, the output pivot bearing, i.e. the pivot bearing near the tool holder, does not withstand the mechanical loads during impact operation. The torques and / or tilting moments acting on the drive train have a particularly strong effect on this bearing, which is furthest away from the drive motor. Tilting moments are caused, for example, by transverse forces acting on the tool. In the aforementioned document, this bearing is designed as a ball bearing and is prone to premature wear. A tilting moment is, for example, a force that acts on the drive train or drive shaft transversely to the longitudinal extent of the drive train and in particular the longitudinal extent of the drive shaft.

[0004] DE 195 36 557 A1 discloses a tool mount for technoscopes with two axially adjacent bearings. DE 10 2017 209 013 A1 discloses a handheld power tool with a locking unit, which includes two different bearings.

[0005] It is therefore the object of the present invention to provide an improved impact wrench.

[0006] To solve the problem, a hand-held power tool according to the technical teaching of claim 1 and an impact wrench according to the technical teaching of claim 15 are provided.

[0007] At this point, however, it should be mentioned that a bearing principle according to the invention can also be used effectively with other types of hand-held machine tools, for example sawing machines, in particular hand-held circular saws, routers or the like.

[0008] The mechanical property can, for example, provide that one shaft bearing can withstand greater mechanical loads than another. Furthermore, the shaft bearings can comprise different bearing types, for example, rolling bearings, plain bearings, or predetermined different rolling bearing types, such as needle bearings and ball bearings. For example, a plain bearing can be provided as the shaft bearing close to the output pivot bearing, while a rolling bearing, in particular a ball bearing or roller bearing, can be provided as the shaft bearing further away.

[0009] The basic idea is that one shaft bearing, for example, has different support properties than the other. For example, one shaft bearing, especially the one located closer to the output pivot bearing, can support a greater support force or tilting moment than the other. Of course, additional shaft bearings, for example, three or four, can be provided.

[0010] According to the invention, the at least one mechanical property comprises different bearing diameters of at least two of the shaft bearings. The different bearing diameters thus comprise, according to the invention, different diameters of an output shaft of the output shaft element and correspondingly different diameters of a bearing receptacle of the drive shaft for the output shaft. The larger bearing diameter can absorb or absorb correspondingly higher forces.

[0011] Advantageously, at least two shaft bearings of the shaft bearing arrangement are supported on the drive shaft with different support lengths relative to the rotational axis. For example, one rolling bearing or plain bearing extends over a greater length relative to the rotational axis than another rolling bearing or plain bearing. Different forces can be supported via the different support lengths.

[0012] An advantageous concept provides for a shaft bearing of the shaft bearing arrangement located closer to the output pivot bearing to be supported on the drive shaft with a larger bearing diameter and / or a shorter support length relative to the axis of rotation than a shaft bearing of the shaft bearing arrangement located further away from the output pivot bearing. In this configuration, for example, the shaft bearing located closer to the output pivot bearing can withstand greater loads in terms of tilting moments or support moments, while the shaft bearing located away from the output pivot bearing must or should absorb a smaller force.

[0013] It is advantageous if there is a distance or free space parallel to the axis of rotation between at least two shaft bearings of the shaft bearing arrangement. This makes it possible to achieve defined bearing properties. For example, the distance can be only a part of the length of a respective bearing section, in particular a plain bearing section, of one or both or more shaft bearings in relation to the axis of rotation, i.e. it can be relatively short or small. However, larger distances or spaces between bearing sections of the shaft bearings are also possible. For example, one shaft bearing can be arranged at one longitudinal end region and another shaft bearing at the other longitudinal end region of the output shaft or the output shaft element.

[0014] It is expedient for at least one shaft bearing of the shaft bearing arrangement to be a plain bearing. However, it is also readily possible for a shaft bearing to be a rolling bearing, in particular a roller bearing, needle bearing, ball bearing, or the like. A configuration in which all shaft bearings of the shaft bearing arrangement are plain bearings is particularly preferred.

[0015] The output shaft element advantageously has at least one plain bearing section, which is mounted on an inner circumference or a bearing receptacle of the drive shaft. For example, the respective length of this plain bearing section or a contact area of ​​the plain bearing section with the bearing receptacle determines a support length of the respective shaft bearing.

[0016] In addition to the plain bearing section, an undercut or an inclined and / or rounded contour is advantageously provided to an adjacent section, in particular another plain bearing section, of the output shaft element. This can, for example, reduce or prevent notch stresses or the like.

[0017] A bearing support of the drive shaft for the output shaft element and / or an output shaft of the output shaft element mounted on the drive shaft advantageously has a stepped contour extending transversely to the axis of rotation. A stepped contour can be achieved, for example, by the output shaft having different bearing diameters in the area of ​​the various shaft bearings.

[0018] Preferably, at least two shaft bearings of the shaft bearing arrangement are supported on the drive shaft with different first and second support lengths. For example, one shaft bearing can be longer than the other shaft bearing with respect to the rotational axis. A bearing section of one shaft bearing, in particular a plain bearing section of one shaft bearing, is correspondingly longer than that of at least one other shaft bearing.

[0019] It is expedient for a shaft bearing of the shaft bearing arrangement located closer to the drive pivot bearing to be supported on the drive shaft with a greater support length than a shaft bearing of the shaft bearing arrangement located closer to the output pivot bearing. Nevertheless, it is advantageous if the shaft bearing with the shorter support length has a larger bearing diameter so that it can absorb greater forces.

[0020] It is advantageous if shaft bearings of the shaft bearing arrangement that are arranged next to one another with respect to the axis of rotation have different bearing clearances transverse to the axis of rotation. For example, a relatively long bearing section of one shaft bearing can have a bearing clearance that is greater than the bearing clearance of a shorter bearing section of another shaft bearing, so that the shaft bearing with the long bearing section is not mechanically overloaded. This is the case, for example, with the following configuration: An advantageous concept provides that a shaft bearing of the shaft bearing arrangement that is arranged closer to the output pivot bearing has a smaller bearing clearance transverse to the axis of rotation than a shaft bearing further away from the output pivot bearing. For example, the shaft bearing arranged closer to the output pivot bearing correspondingly absorbs more forces transverse to the axis of rotation.

[0021] It is also advantageous if a first shaft bearing is supported on the drive shaft with a shorter support length relative to the rotational axis than a second shaft bearing of the shaft bearing arrangement. Nevertheless, a shaft bearing with a shorter support length can support greater forces, for example, if its bearing diameter is correspondingly larger.

[0022] For example, it is expedient if the support length of the shaft bearing arranged closer to the output pivot bearing is smaller than the support length of the shaft bearing arranged further away from the output pivot bearing and / or approximately corresponds to the support length of the output pivot bearing.

[0023] The torque transmission and / or tilting moment transmission and / or bending moment transmission and / or the respective support, for example, the tilting moment support, is optimal. The load on the bearings is low.

[0024] Advantageously, the output shaft element is supported on the drive shaft over a total support length of the shaft bearing arrangement with respect to the rotational axis and on the machine housing over a support length of the output pivot bearing with respect to the rotational axis. With respect to the longitudinal extent of the rotational axis, the total support length of the shaft bearing arrangement is greater than the support length of the output pivot bearing. The total support length is the sum of the support lengths with which the shaft bearings, for example a first and a second shaft bearing, of the shaft bearing arrangement support the output shaft element on the drive shaft element. For example, the total support length is defined by a length of bearing sections of the output shaft, which are mounted on bearing sections of the drive shaft using a plain bearing or rolling bearing.

[0025] The basic idea is that the output shaft or the output shaft element is supported by the shaft bearing arrangement over a comparatively large length or longitudinal extension relative to the axis of rotation. The total support length of the shaft bearing arrangement is therefore greater than the support length of the output pivot bearing. This allows the output shaft element to be optimally supported by the drive pivot bearing as well. The shaft bearing arrangement is therefore arranged between the drive pivot bearing and the output pivot bearing, with the output shaft and the drive shaft element being mounted or supported against each other over a comparatively large length relative to the axis of rotation.

[0026] A preferred embodiment provides that the total support length of the shaft bearing assembly is at least one and a half times or twice as long as the support length of the output pivot bearing. Thus, the total support length of the shaft bearing assembly is significantly longer than that of the output pivot bearing.

[0027] More preferably, the total support length of the shaft bearing assembly is at least three or four times as long, in particular five or six times, and even more preferably seven or eight times as long as the support length of the output pivot bearing. However, the total support length of the shaft bearing assembly can also be nine, ten, or eleven times as long as the support length of the output pivot bearing.

[0028] Furthermore, it is preferred if an output shaft of the output shaft element, which could also be referred to as a bearing shaft, is relatively long but has a small cross-section. For example, the length of the output shaft of the output shaft element supported on the shaft bearing arrangement is at least twice as long, particularly preferably at least three times as long, as the diameter of the output shaft. For example, a rod-shaped or elongated output shaft element projects toward the drive shaft and is supported by the shaft bearing arrangement.

[0029] The handheld power tool is preferably an impact wrench. The drive train then includes a percussion mechanism with a percussion body for driving the output shaft element using rotary impacts.

[0030] Advantageously, the impact body has a bearing mount in which the drive shaft is arranged. The impact body is mounted, for example, on the drive shaft. The shaft bearing assembly also extends into the bearing mount, preferably at least over approximately half its length relative to the axis of rotation. The entire length of the shaft bearing assembly can also be arranged in the bearing mount. It should be noted that the shaft bearing assembly itself does not have to be mounted in the bearing mount, only the output shaft.

[0031] Preferably, the output shaft element penetrates the impact body over part of its longitudinal extent relative to the rotational axis or even protrudes in front of the impact body. For example, an output shaft of the output shaft element, which could also be referred to as a bearing shaft, penetrates the impact body. It is possible for the output shaft to extend over the entire longitudinal extent of the drive shaft. However, it is preferred if the output shaft element does not protrude in front of the impact body in the direction of the drive pivot bearing. For example, the output shaft element extends approximately over half or two-thirds of the longitudinal extent of the impact body.

[0032] It is further advantageous if the impact body is mounted on the drive shaft for axial movement along a bearing area extending along the axis of rotation, and the output shaft element is supported on the drive shaft by the shaft bearing arrangement over part of the length of the bearing area, for example, approximately half of the bearing area or even the entire length of the bearing area. The support of the output shaft element, in particular the output shaft, is advantageously provided in that area of ​​the drive shaft where the axial reciprocating movement of the impact body on the drive shaft takes place.

[0033] Furthermore, the invention provides that the shaft bearing assembly has a bearing receptacle in which an output shaft of the output shaft element is received. The output shaft is supported on the bearing receptacle with respect to the axis of rotation over the entire support length of the shaft bearing assembly. For example, the bearing receptacle extends over the entire length of the output shaft with respect to the axis of rotation of the drive train.

[0034] In principle, the drive shaft could also be provided at an output of the drive motor. This is particularly possible if the drive motor is a so-called direct drive.

[0035] It should be noted at this point that the drive motor is preferably an electric motor, in particular a brushless or electronically commutated motor. However, it is also possible for the drive motor to be, for example, a pneumatic motor or compressed air motor. The bearing concept according to the invention and the optimal support with respect to the machine housing are also feasible with other drive concepts.

[0036] A preferred embodiment of the invention provides that the drive shaft is formed by an output of a gear, for example, a planetary gear or other gear train, which in turn is driven by the drive motor. Thus, the drive motor drives the gear, which in turn provides the drive shaft on which the output shaft element is mounted.

[0037] The shaft bearing arrangement can expediently extend to an end face of a gear wheel of the transmission from which the drive shaft projects and / or extends over the entire length of the drive shaft.

[0038] It is preferred if the drive pivot bearing supports the gear wheel for rotation. However, it is also possible for the drive pivot bearing to support another gear wheel or another component of the transmission, on which the gear wheel is in turn rotatably mounted or which meshes with the gear wheel.

[0039] The drive pivot bearing is conveniently located between the drive motor and the gearbox. For example, the drive pivot bearing represents an input pivot bearing of the gearbox. Apart from the drive pivot bearing and the output pivot bearing, the gearbox may not have any pivot bearings supported on the machine housing or the gearbox housing (discussed later).

[0040] It is further preferred if a drive shaft driven by the drive motor or a drive gear of the transmission driven by the drive motor is arranged in an interior space of the drive pivot bearing. The drive pivot bearing can, for example, support the aforementioned gear wheel rotatably relative to the machine housing and / or a transmission housing, wherein a passage opening for the drive gear is provided on the gear wheel, for example, a planetary gear carrier. The drive gear is, for example, a sun gear of a planetary gear or of the transmission configured as a planetary gear.

[0041] The output pivot bearing preferably comprises a plain bearing or rolling bearing. A roller bearing or needle bearing is preferred.

[0042] It is advantageous if the output pivot bearing is exclusively a radial bearing or at least provides optimal support in the radial direction. With respect to the longitudinal extent of the rotational axis or along the rotational axis, the output pivot bearing preferably provides no support. Thus, the output shaft element is not braked or supported by the output pivot bearing with respect to the rotational axis, but is radially supported.

[0043] It is possible for the output pivot bearing and / or the drive pivot bearing to be fixedly supported on the machine housing of the hand-held power tool, in particular the impact wrench. For example, bearing mounts for the output pivot bearing and / or the drive pivot bearing can be provided on the machine housing.

[0044] Furthermore, it is possible for the output pivot bearing and / or the input pivot bearing to be mounted on a gear housing of the drive train. The gear housing, in turn, is fixedly mounted in the machine housing of the hand-held power tool, in particular the impact wrench. The gear housing can also be fixedly mounted on the machine housing insofar as it protrudes, for example, in front of the machine housing, in particular a front opening of the machine housing.

[0045] It is preferred if the gear housing encapsulates the gear including the impact mechanism.

[0046] The transmission housing comprises, for example, a first and a second capsule element, which are in particular plugged and / or flanged to one another. The shell elements can be designed, for example, as a shell receptacle and a shell cover.

[0047] It is also advantageous if the drive motor is located outside the gearbox housing. However, it is also possible, in principle, for the drive motor to be located inside the gearbox housing.

[0048] The drive pivot bearing is conveniently arranged at an inlet opening of the gearbox housing.

[0049] The output pivot bearing is conveniently located at an output opening of the gearbox housing. Thus, the input and output pivot bearings are advantageously positioned on the input and output sides.

[0050] It should be noted here that a motor bearing can also represent or support the drive pivot bearing. For example, it is possible for a drive motor rotor to be mounted on a pivot bearing relative to the gearbox housing or machine housing, or both, so that it can rotate around the axis of rotation. The pivot bearing can be the drive pivot bearing or support it.

[0051] A further embodiment of the invention provides that the output shaft element has at least one rotation stop for the impact body, for example in the form of laterally projecting cams or wings.

[0052] A control gear is advantageously provided between the impact body and the output shaft for generating an axial movement of the impact body relative to the output shaft along the axis of rotation and / or a rotational movement of the impact body relative to the output shaft when an axial force is applied by a spring actuating the impact body in the direction of the output shaft element.

[0053] The output shaft element advantageously has an anvil body that interacts with the impact body. The tool holder is preferably arranged on the anvil body. However, it is also possible for the anvil body to have the tool holder as a single piece.

[0054] The output shaft mounted on the shaft bearing arrangement is advantageously arranged in a rotationally fixed or rotatable manner on the anvil body.

[0055] The anvil body and the output shaft are preferably made of different materials and / or have different hardnesses. For example, the anvil body may be a hardened or harder component than the output shaft. The output shaft itself is not deformed by the hardening process, meaning its geometry is not affected by the hardening process.

[0056] An embodiment of the invention is explained below with reference to the drawings. They show: Figure 1a side view of a hand-held power tool in the form of an impact wrench, of which Figure 2 shows a cross-section, Figure 3a detail X from Figure 2, Figure 4 a perspective oblique view of a part of a drive train of the hand-held power tool according to the preceding figures, Figure 5 a side view of the drive train according to Figure 4 , Figure 6 a cross section through the drive train according to Figure 5 approximately along a section line BB in Figure 4 or 7 , and Figure 7 a front view of an impact body of the drive train according to the preceding figures.

[0057] A handheld power tool 9 in the form of an impact wrench 10 has a machine housing 11, in whose drive section 12 a drive train 20 is accommodated. A handle section 13 protrudes from the drive section 12 and can be gripped by an operator. The handheld power tool 9 is an electric power tool that operates with electrical current. This can be provided, for example, by an electrical energy storage device 15, in particular a battery pack or the like, and / or an electrical power supply network to which the handheld power tool 9, in particular the impact wrench 10, can be connected, for example, via a connecting cable 115.

[0058] The electrical energy storage device 15, in particular a battery pack, can be connected, for example, to an electrical connection interface 14, which is provided, for example, at the end region of the handle section 13 opposite the drive section 12. However, this is not important in detail. The drive train 20 can be activated using an electrical switch 16, in which an electric drive motor 21 can be energized by pressing the drive switch 16.

[0059] However, instead of the electric drive motor 21, a pneumatic drive motor or a drive motor powered by other energy sources could also be provided at any time. The mechanical components described later could easily be implemented with a drive concept that does not operate with an electric drive motor.

[0060] The drive motor 21 has a stator 22, which includes, for example, an excitation coil arrangement and a laminated core. The drive motor 21 is, for example, a universal motor or, in particular, a brushless or electronically commutated motor. The switch 16 can be used, for example, to activate an electronic commutation device.

[0061] The motor bearings 25, 26 are mounted on bearing receptacles of a motor mount 29 or the stator 22. Extending between the motor bearings 25, 26 are, for example, a permanent magnet arrangement and / or coils and / or a squirrel-cage rotor of the rotor 23.

[0062] A rotor 23 is rotatably mounted relative to the stator 22 by means of motor bearings 25, 26. The motor bearings 25, 26 support a motor shaft 24 of the drive motor 21 so that it can rotate about a rotational axis D.

[0063] At a free end area, for example, near the motor mount 25, a fan wheel 27 is provided, which generates a cooling air flow during operation of the drive motor 21. The cooling air flow cools, for example, the drive motor 21 and / or other components of the drive train 20.

[0064] An output 28 of the drive motor 21 drives a transmission 40 of the drive train 20. The transmission 40 has a transmission drive 41, which is rotationally fixedly coupled to the output 28 of the drive motor 21, for example, by corresponding interlocking contours, by pressing or the like of the output 28 with the transmission drive 41.

[0065] The transmission 40 is preferably designed as a planetary transmission, although other transmission types, in particular gear transmissions or toothed transmissions, are also readily conceivable. The transmission 40 has, for example, a sun gear 42, which is non-rotatably coupled to the transmission drive 41 or is integral with it. The sun gear 42 meshes with planet gears 43, which are rotatably mounted on a planet carrier 45 by means of axle elements 44. The axle elements 44 can be rotatably mounted on the planet carrier 45. It is also possible for the planet gears 43 to be rotatably mounted on the axle elements 44. In this area, for example, ball bearings, needle bearings, or other rolling bearings, but also plain bearings, are readily conceivable.

[0066] The planet gears 43 are received in planet gear receptacles 46 of the planet carrier 45. The radial outer circumference of the planet gears 43 each projects radially outward in front of a planet gear receptacle 46, so that the planet gears 43 can mesh with the teeth of a ring gear 54. For example, the planet carrier 45 has opposing walls 47A, 47B or end walls in which bearing receptacles 47 or holding receptacles for the axle elements 44 are provided. The planet gear receptacles 46 are provided between the walls 47A, 47B. A peripheral wall 47C of the planet carrier 45 has recesses in which the planet gear receptacles 46 are provided.

[0067] The planetary carrier 45 is rotatably mounted on a gear housing 51 of the gear box 40 and thus also relative to the machine housing 11 by means of a drive pivot bearing 50. The gear housing 51 is supported on the machine housing 11.

[0068] For example, the gear housing 51 has a bearing mount 52 for the drive pivot bearing 50. The bearing mount 52 and the drive pivot bearing 50 are provided on the side of the gear 40 facing the drive motor 21.

[0069] In addition to the bearing support 52, a ring gear support area 53 is provided for the ring gear 54. The ring gear 54 is thus supported and held in a rotationally fixed manner with respect to the transmission housing 51.

[0070] At this point, it should be mentioned that a transmission with a ring gear is also possible within the scope of the invention, which can be brought into engagement or disengaged with different gear stages or planets of a transmission, for example by a displacement parallel to the axis of rotation D or another switching mechanism, in order to realize, for example, different gears or switching stages of a transmission.

[0071] The planet carrier 45 serves to drive a drive shaft 48. The drive shaft 48 projects, for example, in front of an end face of the planet carrier 45 in the direction of a tool holder 90 of the hand-held power tool 9, in particular of the impact wrench 10.

[0072] While the impact wrench 10 has a percussion mechanism 60 in which the shaft bearing assembly 49 described above can be advantageously used, it is readily possible for a shaft bearing assembly according to the invention, for example the shaft bearing assembly 49, to also be advantageously used in other types of hand-held power tools, such as sawing machines or the like.

[0073] The drive shaft 48 continues to protrude in the direction of the impact mechanism 60 of the impact wrench 10.

[0074] The drive shaft 48 protrudes, for example, from the wall 47B. The drive shaft 48 is preferably a body integrally connected to the wall 47B, for example, but could also be a component attached thereto. In any case, the drive shaft 48 is firmly connected to the planet carrier 45, preferably in one piece.

[0075] The impact mechanism 60 drives an output shaft element 80. The output shaft element 80 engages with an output shaft 81 in a bearing receptacle 149 of the shaft bearing assembly 49 of the drive shaft 48 of the gear 40. The output shaft 81 is rotatably mounted in the bearing receptacle 149, preferably by means of a plain bearing. However, the shaft bearing assembly 49 could also be a roller bearing, in particular a nail bearing, which facilitates or improves the rotatable mounting of the output shaft 81 in the bearing receptacle 149.

[0076] The impact mechanism 60 comprises an impact body 61, which is driven by the drive shaft 48 of the gear 40. The drive shaft 48 engages in a bearing receptacle 61A of the hammer body 61. A front side or a free end region of the drive shaft 48 projects up to a front side 61B of the impact body 61. The two front sides of the drive shaft 48 and the impact body 61 are aligned, for example, in the position shown in Figure 2 each other.

[0077] A control gear 63 is provided between the gear 40, in particular the drive shaft 48, and the impact body 61. For example, control cams 63A, 63B are provided on the drive shaft 48, which have an overall V-shaped or helical profile. Drive bodies 62, for example, balls, are provided in the control cams 63A, 63B. The drive bodies 62 engage with control surfaces 64 of the impact body 61, which are provided, for example, on the end face 61B. The control surfaces 64 preferably also include control cams 65, for example, V-shaped or helical grooves.

[0078] During a rotational movement of the drive shaft 48, the drive bodies 62 move back and forth in the V-shaped grooves or control curves 63, causing the impact body 61 to rotate against the force of a spring 69.

[0079] The control curves 63A, 63B and the control curves 65 are V-shaped in opposite directions, which can be seen, for example, in the Figures 4 and 5can be clearly seen. It would be sufficient for the control cams 63A, 63B on the one hand or the control cams 65 on the other hand to be designed as V-shaped or helical grooves. However, the helical or V-shape of the control cams 63A, 63B, 65 produces a particularly large stroke in relation to the axis of rotation D or a particularly wide axial adjustment of the impact body 61 in relation to the drive shaft 48 or a strong rotational acceleration of the impact body 61 when it is axially urged towards the anvil body 65 by the spring 69. The control gear 63 is therefore in principle a gear which converts an axial movement of the impact body 61 due to the spring 69 into a rotational movement and thus an impact impulse about the axis of rotation D, orin the opposite direction, screwing of the impact body 61 along the drive shaft 48 away from the anvil body 75, whereby the spring 69i is tensioned until the impact body 61 can rotate over the anvil body 65 in order to subsequently carry out the aforementioned rotary blows on the anvil body 65.

[0080] The spring 69 is supported on the one hand on the planet carrier 45, in particular by means of a bearing disk or via a bearing disk 73. Furthermore, the spring 79 is supported on the impact body 61. It engages, for example, in a spring receptacle 68 on the rear side or the side of the impact body 61 facing away from the front side 61B. Preferably, a bearing 70, in particular a ball bearing with balls 72, is provided between the spring 69 and the spring receptacle 68, or at least the support surface for the spring 69 in the spring receptacle 68. A support body 72, for example a disk, is preferably provided between the spring 69 and the balls of the bearing 71, which could of course also be a rolling bearing with other rolling elements, in particular rollers. The control cams 63 and the control surfaces 64 are designed, for example, as V-shaped grooves running in opposite directions to one another. When the impact body 61 reaches its position spaced from the gear 40 or in Figure 2 shown front position, in which the impact body 61 is arranged at the front end area of ​​the drive shaft 48, the control balls or drive bodies 42 are in the respective tips of the V-shaped control curves 63 or the control surfaces 64. If a greater counter-torque than a limit counter-torque is exerted on the output shaft element 80 from the outside, this leads to an axial movement in a direction away from the output shaft element 80, against the spring force of the spring 69, for example in Figure 2 and Figure 7to the left, so that the impact body 61 rotates past the output shaft element 80 and then moves forward again into a forward position under the spring force of the spring 69. In this case, output drive projections 66 of the impact body 61 act on the output shaft element 80, namely on an anvil element or an anvil body 75 thereof. The anvil body 75 has output drive projections 76 arranged between the drive drive projections 66. Impact surfaces 67 of the drive drive projections 66 act laterally on the output drive projections 76 and generate a sudden torque on the output shaft element 80, so that it is rotationally driven or subjected to rotational impacts in the respective direction of rotation of the drive shaft 48.

[0081] The control cams 65 and 63A, 63B double, so to speak, the axial movement path of the impact body 61 with respect to the drive shaft 48.

[0082] A tool holder 90 for a tool 19, for example a drill or in particular a screwdriver bit, is provided on the output shaft element 80. The tool holder 90 has a plug-in receptacle 92 on a receptacle body 91. The receptacle body 91 extends away from the output shaft element 80 in an extension of the axis of rotation D to the output shaft 81. The receptacle body 91 could be a body connected to the output shaft element 80; in the present case, the receptacle body 91 is preferably integral with the output shaft element 80 and in particular the output shaft 81. This ensures particularly high torsional rigidity and stability. An actuating element 93 for actuating locking elements 94 is provided on the outer circumference of the receptacle body 91.

[0083] The actuating element 93 is preferably designed as a sleeve that is mounted on the receiving body 91 so as to be displaceable along the rotational axis D. A spring 95 is supported on the receiving body 61 in the region of an insertion opening of the plug-in receptacle 92 by means of support disks 96, 97 with respect to the rotational axis D. The other, opposite longitudinal end region of the spring 91 urges the actuating element 93 into a locking position, in which it urges locking elements 94, in particular balls, radially inward into the plug-in receptacle 92 by means of a holding element 98, so that the locking elements 94 engage positively in locking receptacles 119 of the tool 19. As a result, the tool 19 is locked in the plug-in receptacle 92 and secured against withdrawal.

[0084] When the actuating element 93 is moved against the force of the spring 95 toward the insertion opening of the plug-in receptacle 92, i.e., into an unlocking position, the locking elements 94 can move radially outward from the plug-in receptacle 92 into the area of ​​a release receptacle 99 of the actuating element 93, so that the positive engagement of the locking elements 94 with the locking receptacles 119 of the tool 19 is canceled. The tool 19 can then be removed from the insertion opening or plug-in receptacle 92.

[0085] Insertion of the tool 19 is possible by means of a holding element 98 even if the actuating element 93 is not actuated in the direction of its unlocked position, e.g., to the right in the drawing, against the force of the spring 95. When inserting the tool 19 into the plug-in receptacle 92, the locking elements 94 can actuate the holding element 98 against the force of the spring 95 in the direction of the free end or the insertion opening of the plug-in receptacle 92, whereby the locking elements 94 can move further radially outwards and displace the holding element 98 against the force of the spring 95, thus enabling insertion of the tool 19 into the plug-in receptacle 92.

[0086] The output shaft element 80 is supported on the machine housing 11 by means of an axial bearing 82. The axial bearing 82 is supported, for example, on a wall section 17 of the machine housing 11. The wall section 17 is provided in the region of a through-opening 18 of the machine housing 11, at which the drive train 20 with the tool holder 90, in particular the holder body 91, protrudes in front of the machine housing 11. However, generally no force is exerted on the axial bearing 82 because the travel or movement path of the impact body 61 on the output shaft 81 is defined by the control gear 63.

[0087] An output pivot bearing 83, for example a ball bearing or, in particular, a plain bearing, is provided at the passage opening 18. The output pivot bearing is preferably a radial bearing, in particular a bearing with an exclusively radial bearing. The output pivot bearing 83 mounts the drive train 20 in the area of ​​the tool holder 90 relative to the machine housing 11 so that it can rotate about the axis of rotation D. The other bearing relative to the machine housing 11 is provided by the drive pivot bearing 50, which are spaced apart by a distance A. At the distance A between the output 28 of the drive motor 30 on the one hand and the tool holder 90 on the other hand, in particular on the holder body 91, there is no pivot support of the drive train 20 on the machine housing 11. At most, the planet gears 43 on the ring gear 54, which in turn is supported on the ring gear support area 53 of the gear housing 51, experience a certain degree of radial support.The ring gear support area 53 is radially supported on the outside by a housing cover 56, which is mounted on a housing base body 55 of the gear housing 51 and covers it in the area of ​​the impact mechanism 60. The gear 40 is housed in the housing base body 55. The housing base body 55 engages in a receptacle 57 of the housing cover 56. The ring gear support area 53 is supported radially on the outside in the area of ​​the receptacle 57.

[0088] The housing cover 56 forms a front area of ​​the machine housing 11 and has, for example, the aforementioned wall section 17 and the through-opening 18. The machine housing 11 and the gear housing 51 could easily be made in one piece or have identical components. In any case, a structurally stable support or rotary mounting of the drive train 20 is provided by the input rotary bearing 50 and the output rotary bearing 83 with respect to a radial bearing or rotary mounting relative to the rotational axis D at a distance A. With respect to the machine housing 11, the two rotary bearings 50, 83 are therefore decisive with regard to the radial bearing or rotary mounting of the drive train 20 relative to the machine housing 11.

[0089] The shaft bearing arrangement 49 extends over part of the length of the drive shaft 48, i.e. over part of the section between the planet carrier 45 and the end face of the anvil body 75. For example, the shaft bearing arrangement 49 extends approximately over half the length of the drive shaft 48. Thus, the shaft bearing arrangement 49 is so long that, with respect to the axis of rotation D, a total support length SW of the shaft bearing arrangement 49 is considerably greater, for example three to four times as great as a support length SD of the output pivot bearing 63. The output pivot bearing 63 is therefore a particularly short pivot bearing with respect to the axis of rotation D. As a result, the impact wrench 10, in particular its drive train 20, is very short with respect to the axis of rotation D.

[0090] It is also advantageously provided that a diameter of the output shaft 81 is relatively small, in any case significantly smaller than a length of the output shaft 81. In any case, a length of the output shaft 81, which is supported by the shaft bearing arrangement 49, is at least three to four times, preferably five or six times, as large as the smaller diameter DAB or the larger diameter DAA of the output shaft 81.

[0091] At this point, for a better understanding, it should be noted that the support length SD, which can be easily Figure 3 recognizes, is also particularly short because a seal 84, in particular a shaft seal, is additionally arranged next to or on the output rotary bearing 83. The seal 84, for example, lies sealingly radially on the outside of the output shaft element 80, in particular the receiving body 91.

[0092] The output shaft 81 is rotatably mounted in the bearing holder 149.

[0093] The shaft bearing arrangement 49 has shaft bearings 49A, 49B arranged spaced apart from one another or adjacent to one another with respect to the axis of rotation D.

[0094] The shaft bearing 49A is arranged closer to the output pivot bearing 83, and the shaft bearing 49B is arranged closer to the drive pivot bearing 50. While the shaft bearing 49A is arranged directly next to the output pivot bearing 83, the shaft bearing 49B is spaced longitudinally from the drive pivot bearing 50 with respect to the rotation axis D. In particular, the shaft bearing 49B extends to a longitudinal center of the bearing receptacle 149 with respect to the rotation axis D.

[0095] On the output shaft, output shaft sections 81A, 81B, which are arranged side by side with respect to the rotational axis D, are provided with bearing elements 86, 87 or are designed as bearing elements 86, 87. The bearing elements 86, 87 are rotatably mounted in bearing receptacles 186, 187, which form parts of the bearing receptacle 149. Thus, the shaft bearings 49A, 49B are each plain bearings, but they have different mechanical designs.

[0096] The output shaft section 81A is shorter than the output shaft section 81B. Likewise, the bearing elements 86, 87 and the associated bearing mounts 186, 187 are of different lengths relative to the rotational axis D. Accordingly, the shaft bearings 49A, 49B have different support lengths SWA and SWB. Thus, the shaft bearing 49A is supported on the bearing mount 149 with a shorter support length SWA than the shaft bearing 49B with its support length SWB.

[0097] Nevertheless, the shaft bearing 49A carries a greater "support load," thus absorbing a higher tilting moment or support moment, than the shaft bearing 49B. A bearing diameter DAA of the shaft bearing 49A, i.e., a diameter of the bearing element 86 or bearing seat 186, is larger than a bearing diameter DAB of the shaft bearing 49B, i.e., its bearing element 87 and bearing seat 187. Thus, the shaft bearing 49A can absorb greater forces than the shaft bearing 49B.

[0098] The output shaft 81 has a stepped shape with respect to the rotational axis D, with a larger diameter or a larger step being provided close to the anvil body 75.

[0099] In front of the bearing element 86, the bearing element 87 protrudes in the manner of a support shaft to the drive pivot bearing 50.

[0100] The particularly resilient shaft bearing 49A has a greater load-bearing capacity than the shaft bearing 49B with respect to forces acting transversely to the rotational axis D. For example, if the impact wrench 10 falls to the ground, a high transverse load or impact load can occur on the tool holder 90, particularly when the tool 19 is arranged on the tool holder 90. Under such a load, the output shaft element 80 experiences a pivoting force or pivoting movement around the output pivot bearing 83, which is short with respect to the rotational axis D, but which is optimally supported by the shaft bearing 49A.

[0101] Furthermore, for example, the spring 69 generates a tilting moment transverse to the axis of rotation D, which is, however, supported by the shaft bearing 49A with a comparably loadable capacity.

[0102] In order for the shaft bearing 49A to primarily absorb a force load when forces act on the output shaft element 80 transversely to the axis of rotation D, it can be provided that the shaft bearing 49A has a smaller bearing play transversely to the axis of rotation D than the shaft bearing 49B.

[0103] Furthermore, it is advantageous if the shaft bearings 49A, 49B are spaced apart from the rotational axis D. For example, there is a space between the support lengths SWA, SWB. There, a transition area 89 is located between the bearing elements 86, 87, for example, an undercut, a radial recess relative to the rotational axis D, or the like. The transition 89 is preferably a continuous, rounded, and / or beveled transition in order to avoid or reduce loads, such as notch stresses or the like, between the bearing elements 86, 87, which are integral with the output shaft 81.

[0104] It is also advantageous if a radial recess 88, for example, an undercut, is provided between the anvil body 75 and the shoulder of the output shaft 81, thus the bearing element 86. A low notch stress should also be present there. However, it is advantageous if, instead of or in addition to the undercut, a generously rounded transition area is provided between the anvil body 75 and the shoulder of the output shaft 81, thus the bearing element 86.

Claims

1. A handheld machine tool, in particular an impact driver, having a drive train (20) for driving a tool receptacle (90), provided for receiving a tool (19), in particular a screwdriver tool, about a rotation axis (D), wherein the drive train (20) comprises a drive motor (21), an output shaft element (80), on which the tool receptacle (90) is arranged, and a drive shaft (48), which is drivable by the drive motor (21), for driving the output shaft element (80), wherein the output shaft element (80) is rotatably mounted by means of an output pivot bearing (83) and the drive shaft (48) is rotatably mounted by means of a drive pivot bearing (50) about the rotation axis (D) in respect of a machine housing (11), and wherein the output shaft element (80) is rotatably mounted by means of a shaft bearing arrangement (49) on the drive shaft (48) about the rotation axis (D), wherein the shaft bearing arrangement (49) comprises a bearing receptacle (149) in which an output shaft (81) of the output shaft member (80) is received, wherein the output shaft is supported on the bearing receptacle (149) in relation to the rotation axis (D) of the shaft bearing arrangement (49), and wherein the shaft bearing arrangement (49) comprises at least two shaft bearings (49A, 49B) which are arranged adjacent to each other with respect to the rotation axis (D), characterized in that the at least two shaft bearings (49A, 49B) differ in at least one mechanical property, the at least one mechanical property comprising different bearing diameters of at least two of the shaft bearings (49A, 49B), and in that the different diameters comprise different diameters of the output shaft (81) of the output shaft member (80) and correspondingly different diameters of the bearing seat (149) of the input shaft (48) for the output shaft (81).

2. The hand-held machine tool according to claim 1, characterized in that the at least two shaft bearings (49A, 49B) of the shaft bearing arrangement (49) are supported on the drive shaft (48) at different support lengths (SWA, SWB) in relation to the rotation axis (D).

3. The hand-held machine tool according to claim 1 or 2, characterized in that a shaft bearing (49A, 49B) of the shaft bearing arrangement (49) which is arranged closer to the output pivot bearing (83) has a greater bearing diameter and / or is supported at a shorter support length (SWA) on the drive shaft (48) in relation to the rotation axis (D) than a shaft bearing (49A, 49B) of the shaft bearing arrangement (49) which is farther away from the output pivot bearing (83) and / or in that there is a distance (85) or free space parallel to the rotation axis (D) between at least two shaft bearings (49A, 49B) of the shaft bearing arrangement (49).

4. The hand-held machine tool according to any one of the preceding claims, characterized in that at least one bearing (49A, 49B) of the shaft bearing arrangement (49) is a slide bearing, wherein it is advantageously provided that the output shaft member (80) has at least one slide bearing section which is mounted on an inner circumference or a bearing receptacle of the drive shaft (48), wherein adjacent to the slide bearing section, there is preferably a relief groove or an oblique and / or rounded contour (88) to an adjacent section, particularly another slide bearing section, of the output shaft member (80).

5. The hand-held machine tool according to any one of the preceding claims, characterized in that a bearing receptacle (149) of the drive shaft (48) for the output shaft member (80) and / or an output shaft (81) of the output shaft member (80) mounted on the drive shaft (48) comprises a stepped contour extending transversely to the rotation axis (D).

6. The hand-held machine tool according to any one of the preceding claims, characterized in that at least two shaft bearings (49A, 49B) of the shaft bearing arrangement (49) are supported on the drive shaft (48) at different first and second support lengths (SWA, SWB) in relation to the rotation axis (D).

7. The hand-held machine tool according to any one of the preceding claims, characterized in that a shaft bearing (49B) of the shaft bearing arrangement (49) arranged closer to the drive pivot bearing rests on the drive shaft (48) at a greater support length (SWB) than a shaft bearing (49A) of the shaft bearing arrangement (49) arranged closer to the output pivot bearing (83).

8. The hand-held machine tool according to any one of the preceding claims, characterized in that shaft bearings (49A, 49B) of the shaft bearing arrangement (49) arranged next to each other relative to the rotation axis (D) have different bearing clearances across the rotation axis (D) and / or in that a shaft bearing (49A) of the shaft bearing arrangement (49) arranged closer to the output pivot bearing (83) has a smaller bearing clearance across the rotation axis (D) than a shaft bearing (49B) located farther away from the output pivot bearing (83).

9. The hand-held machine tool according to any one of the preceding claims, characterized in that a first shaft bearing (49A) having a shorter support length (SWA) in relation to the rotation axis (D) than a second shaft bearing (49B) of the shaft bearing arrangement (49) is supported at the drive shaft (48) and / or in that the support length (SWA) of the shaft bearing (49A) arranged closer to the output pivot bearing (83) is smaller than the support length (SWB) of a shaft bearing (49B) arranged farther away from the output pivot bearing (83) and / or approximately matches the support length (SD) of the output pivot bearing (83).

10. The hand-held machine tool according to any one of the preceding claims, characterized in that the output shaft member (80) is supported over an overall support length (SW) of the shaft bearing arrangement (49) in relation to the rotation axis (D) on the drive shaft (48) and over a support length (SD) of the output pivot bearing (83) in relation to the rotation axis (D) at the machine housing (11), and the overall support length (SW) of the shaft bearing arrangement (49) is greater than the support length (SD) of the output pivot bearing (83) in relation to the longitudinal extension of the rotation axis (D), the overall support length (SW) of the shaft bearing arrangement (49) being advantageously at least one and a half or twice, further advantageously at least three times or four times, in particular five times or six times, particularly preferably seven times or eight times, further preferably nine times or ten times as great as the support length (SD) of the output pivot bearing (83) with respect to the longitudinal extension of the rotation axis (D).

11. The hand-held machine tool according to any one of the preceding claims, characterized in that a length of the output shaft (81) of the output shaft member (80) supported on the shaft bearing arrangement (49) is at least twice as great, preferably at least three times as great, as a diameter of the output shaft (81).

12. The hand-held machine tool according to any one of the preceding claims, characterized in that the drive train (20) includes an impact mechanism (60) with an impactor (61) for driving the output shaft member (80) by means of rotary impacts.

13. The hand-held machine tool according to claim 12, characterized in that the impactor (61) has a bearing receptacle (61A) in which the drive shaft (48) is arranged and into which the shaft bearing arrangement (49) extends at least over half its length in relation to the rotation axis (D) and / or in that the output shaft member (80), particularly an output shaft (81), of the output shaft member (80) penetrates the impactor (61) over a portion of its entire longitudinal extension in relation to the rotation axis (D), or projects from the impactor (61) and / or in that the impactor (61) is axially movably mounted on the drive shaft (48) along a bearing section on the drive shaft (48) extending along the rotation axis (D) and the output shaft member (80) is supported over at least a portion of the length of the bearing section on the drive shaft (48) by means of the shaft bearing arrangement (49).

14. The machine tool according to any one of the preceding claims, characterized in that the shaft bearing arrangement (49) is arranged in an interior space of the machine housing (11) and / or in that the shaft bearing arrangement (49) is arranged between the output pivot bearing (83) and the drive motor (21).

15. An impact driver having a drive train (20) for driving a tool receptacle (90) provided for receiving a tool (19), particularly a screwdriver tool, about a rotation axis (D), wherein the drive train (20) comprises a drive motor (21) and an impact mechanism (60), wherein the drive train (20) comprises a drive shaft (48) which can be driven by the drive motor (21) for driving an impactor (61) of the impact mechanism (60), wherein the impactor (61) is provided for driving an output shaft member (80) on which the tool receptacle (90) is arranged by means of rotary impacts, wherein the output shaft member (80) is rotatably mounted about the rotation axis (D) by means of an output pivot bearing (83), and the drive shaft (48) is rotatably mounted about the rotation axis (D) by means of a drive pivot bearing (50) in relation to a machine housing (11), and wherein the output shaft member (80) is rotatably mounted about the rotation axis (D) by means of a shaft bearing arrangement (49) on the drive shaft (48), wherein the shaft bearing arrangement (49) comprises a bearing receptacle (149) in which an output shaft (81) of the output shaft member (80) is received, wherein the output shaft is supported on the bearing receptacle (149) in relation to the rotation axis (D) of the shaft bearing arrangement (49), and wherein the shaft bearing arrangement (49) comprises at least two shaft bearings (49A, 49B) which are arranged adjacent to each other with respect to the rotation axis (D), characterized in that the at least two shaft bearings (49A, 49B) differ in at least one mechanical property, the at least one mechanical property comprising different bearing diameters of at least two of the shaft bearings (49A, 49B), and in that the different diameters comprise different diameters of the output shaft (81) of the output shaft member (80) and correspondingly different diameters of the bearing seat (149) of the input shaft (48) for the output shaft (81).