CN108290265B

CN108290265B - Hand-held power tool

Info

Publication number: CN108290265B
Application number: CN201680071717.2A
Authority: CN
Inventors: M.希格林
Original assignee: Festool GmbH
Current assignee: Festool GmbH
Priority date: 2015-12-08
Filing date: 2016-12-05
Publication date: 2021-06-08
Anticipated expiration: 2036-12-05
Also published as: EP4292760A3; WO2017097701A1; CN108290265A; EP3359334B1; DE112016004577A5; EP4292760A2; DE102015121305A1; EP3359334A1

Abstract

The invention relates to a hand-held power tool, in particular a grinder (10), having an eccentric gear mechanism (40) arranged in a machine housing (11) and an electric or pneumatic drive motor (30) for rotationally driving a drive shaft (35) of the eccentric gear mechanism (40) about a drive axis (A), wherein the eccentric gear mechanism (40) has a tool shaft (50) which, for performing an eccentric movement, is eccentrically rotatably mounted on the drive shaft (35) by means of at least one tool shaft bearing (42,44) and has a tool receptacle (51) for a disk tool (14), wherein a positive rotation guide (54) is provided which, in a positive rotation eccentric mode of the tool shaft (50), forces a rotational movement relative to the machine housing (11) by rolling a rolling body (55) of the positive rotation guide (54) against a further rolling body (54) of the positive rotation guide (54) The bodies (57) roll, wherein the rolling bodies (57) are supported on the machine housing (11) and the other rolling bodies are supported on the tool shaft (50). An idle device (62) is arranged between at least one of the rolling bodies (57) and the tool shaft (50) or the machine housing (11), said idle device coupling the at least one rolling body (57) to the machine housing (11) or the tool shaft (50) in a rotationally fixed manner in a first rotational direction of the tool shaft (50) corresponding to a locking direction of the idle device (62), so that the rolling bodies (55) supported on the tool shaft (50) can roll on the other rolling bodies (57) supported on the machine housing (11) and can be released in a rotationally fixed manner in a second rotational direction of the tool shaft (50) corresponding to the idle direction of the idle device (62), so that the tool shaft (50) can rotate relative to the machine housing (11) without the rolling bodies (55,57) rotating relative to one another.

Description

Hand-held power tool

Technical Field

The invention relates to a Hand-held power tool (Hand-held Werkzeugmaschine), in particular a sander and/or a polisher, having an eccentric gear mechanism arranged in a machine housing and an electric or pneumatic drive motor for rotationally driving a drive shaft of the eccentric gear mechanism about a drive axis, wherein the eccentric gear mechanism has a tool shaft which, for performing an eccentric movement, is eccentrically rotatably mounted on the drive shaft by means of at least one tool shaft bearing and has a tool receptacle for a disk-type tool, in particular a grinding or polishing disk, wherein a positive rotation guide is provided which, in a positive rotation eccentric mode of the tool shaft, forces a rotational movement with respect to the machine housing, by rolling elements of the positive rotation at further rolling elements of the positive rotation guide, wherein the rolling bodies are supported at the machine housing and the other rolling bodies are supported at the tool shaft.

Background

Such a hand-held power tool is described, for example, in DE 102010012025. An operator may manually switch the machine between the forced rotation eccentric mode and the idle eccentric mode. In the forced rotation eccentric mode, the tool shaft performs a defined rotational movement by rolling the planet wheels connected with the tool shaft at a hollow wheel supported at the machine housing. When the hollow wheel is out of engagement with the planet wheel, the tool shaft can rotate relatively freely and is carried by the at least one tool shaft support.

However. Switching between operating modes is costly.

Disclosure of Invention

The object of the present invention is therefore to provide an improved operating design for a hand-held power tool, in particular a sander or polishing machine.

In order to solve this object, provision is made in a hand-held power tool of the type mentioned at the outset for an idle device (freeiaffeinating, sometimes also referred to as a one-way clutch device or a free-running device) to be arranged between at least one of the rolling bodies and the tool shaft or the machine housing, which idle device supports, in particular rotationally fixedly couples, the at least one rolling body at the machine housing or the tool shaft in a first rotational direction of the tool shaft corresponding to a locking direction of the idle device by means of a supporting force suitable for the rolling of the other rolling bodies, so that the rolling body supported at the tool shaft can be rolled at the other rolling body supported at the machine housing, and is rotationally released in a second rotational direction of the tool shaft corresponding to a free-running direction of the idle device, so that the tool shaft can be rotated relative to the machine housing without the rolling bodies rotating relative to one another and/or the rolling body supported at the tool shaft can be rotationally carried along with the rolling body supported at the tool shaft The rolling bodies at the machine housing and/or the rolling bodies associated with the tool shaft can be held completely or substantially rotationally fixed (rotationbest) by the rolling bodies associated with the machine housing.

In the second direction of rotation, it is possible for the rolling bodies supported on the tool shaft to carry them rotatably along with them supported on the machine housing. However, it is also possible for the rolling bodies associated with the tool shaft to be rotatable in the second direction of rotation, so that they can be supported on the machine housing and the non-rotatable rolling bodies can be held in a fixed or substantially fixed position in the second direction of rotation.

The basic concept here is that the forced-rotation eccentric mode can be switched on or off by reversing the direction of rotation of the tool shaft. That is, the forced rotation eccentric mode is active in the first rotational direction of the tool shaft, so that the forced rotation guide of the tool shaft can be said to force a defined rotation relative to the machine housing. The freewheel device latches in this case. As a result, the rolling bodies can no longer rotate freely relative to the component, i.e. the machine housing or the tool shaft, which is supported by the rolling bodies in this case via the freewheel.

However, when the tool shaft rotates in the second direction of rotation, the roller body which is still supported in the first direction of rotation of the tool shaft or in the blocking direction of the freewheel is released, i.e. can rotate freely and is held stationary, for example, by being entrained by or supported at other roller bodies. It is thereby possible that the tool shaft is no longer guided by the forced rotation guide, i.e. is no longer in the forced rotation eccentric mode.

That is, the forced rotation eccentric mode is activated in the locking direction of the idle rotation device, and is deactivated in the idle rotation direction of the idle rotation device.

In the forced rotation eccentric mode, the tool shaft expediently executes a forced rotation about the drive axis by means of a forced rotation guide, which changes its rotational angular position relative to the machine housing of the hand-held power tool.

In the forced rotation eccentric mode, it is expediently provided that the freewheel is completely blocked, i.e. the mobility of the blocked rolling bodies is completely suppressed relative to the component, which is supported there via the freewheel. In this case, the ring gear can no longer rotate relative to the machine housing, for example. However, it is also possible that a lower support force with respect to the complete blocking (Blockade) of the rolling elements is provided by the freewheel device in the locked position, but rather a rotational blocking (drehheimmung). The rolling bodies are then not completely prevented from rotating relative to the supporting component, i.e. the machine housing or the tool shaft, but rather are prevented from rotating freely, i.e. with regard to the rotatability. That is, the supporting force may be slightly less than the force necessary for complete blocking or prevention of the relative movement of the supported rolling bodies with respect to the supporting component (machine housing or tool shaft).

When the forced rotation eccentric mode is turned off, for example, there is a free rotation eccentric mode. For example, it is provided that the tool shaft is in a free-rotation eccentric mode in the second rotational direction, in which the tool shaft performs a rotational movement when the drive shaft rotates due to a bearing friction of the at least one tool shaft bearing and is freely rotationally movable about the drive axis. It is understood that the mobility is always also limited by a certain bearing friction, but in this sense is understood to mean a free mobility, i.e. the rolling elements which previously still have a supporting effect can be moved by further rolling elements.

The hand-held power tool expediently has a braking device for braking the tool shaft or a disk tool arranged on the tool shaft. The braking means may comprise, for example, a braking body, a sealing collar (Dichtmanschette) or another braking means which acts on the braking means at the tool shaft or the tool or both, in particular for operation of the hand-held power tool with the forced rotation eccentric mode switched off.

Preferably, one of the rolling bodies is a ring gear and the other rolling bodies are or have planetary gears. The planet wheels can be accommodated in a hollow wheel and roll on this hollow wheel. For example, a ring gear is associated with the machine housing, while a planet gear is associated with the tool shaft. However, the opposite configuration is also possible, in which planetary wheels are provided on the machine housing, around which a ring gear, as it were, is looped, which is itself fixed on the tool shaft.

In principle, however, it is also conceivable for one of the rolling bodies to be designed as a central wheel, around which the rolling bodies designed as planetary wheels roll, so to speak, around or in planetary wheels.

Preferably, the rolling bodies have teeth, so that the rolling bodies mesh with one another with their teeth. However, it is also possible that when the adjustment is made in the first rotational direction and the freewheel assumes the blocking direction or the blocking position, the rolling bodies move along in a friction-fitting manner with respect to one another due to the friction fit, i.e. they roll over or roll at the other rolling bodies in a friction-fitting manner.

For example, it is possible for only one of the rolling bodies to be supported by means of an idle device with respect to the tool shaft or with respect to the machine housing. That is, only a single idle device may therefore be provided, which is also shown in the figures.

The hand-held power tool may also have a plurality of idle devices. It is thus possible, for example, for a freewheel device to be arranged between the rolling bodies associated with the tool shaft and the tool shaft, while a further freewheel device is arranged between the machine housing and the rolling bodies associated with the machine housing. For example, it is possible that one of the freewheel devices completely prevents the rolling bodies arranged at it from rotating in the locked position, while the other freewheel device brakes, i.e., prevents the rolling bodies arranged at it from rotating or from being rotationally movable in the locked position. That is, the other lost motion devices do not contribute to a complete retardation of the rotational movement of the rolling bodies associated therewith.

It is possible that the rolling bodies, which are supported in a rotationally fixed manner by means of the at least one freewheel device with respect to the machine housing or the tool shaft, can be rotated with respect to the machine housing or the tool shaft by means of a rotary bearing, in particular a rolling bearing, particularly preferably a geobearing (Kugellager), when the freewheel device occupies a freewheel direction or the tool shaft is rotated in the second direction of rotation.

Preferably, the freewheel device is arranged on or forms a component of a bearing by means of which the rolling bodies are rotatably supported with respect to the machine housing or the tool shaft. For example, it is possible to use a support, in particular a rotary support, particularly preferably an earth support, with an integrated idle device.

Preferably, the at least one tool shaft support has a first tool shaft support and a second tool shaft support, which are spaced apart from one another with respect to the drive axis or longitudinal extension of the drive shaft. It is particularly preferred if the two tool shaft supports are arranged at respective longitudinal end regions of the tool shaft and/or of the drive shaft.

It is possible that the tool shaft is a hollow shaft, the drive shaft being arranged in the interior of the hollow shaft. It is also possible for the drive shaft to be arranged in or engage into the inner space of the tool shaft. The tool shaft can be mounted eccentrically, for example, on the outside of the drive shaft.

A variant is preferred in which the drive shaft has an interior space, for example designed as a hollow shaft, in which the tool shaft is arranged. Advantageously, the drive shaft has a hollow shaft or is designed as a hollow shaft, in which the tool shaft is arranged.

Expediently, the tool shaft is accommodated eccentrically in the drive shaft. At least one tool shaft bearing is arranged, for example, in the interior of the drive shaft and supports the tool shaft.

The following configuration is possible not only when the drive shaft is a hollow shaft that accommodates the tool shaft, but also when the tool shaft is a hollow shaft that accommodates the drive shaft therein.

It is expediently provided that the tool shaft projects in front of the drive shaft at a region facing away from the tool receptacle, and that one of the rolling bodies carries, for example, a planetary or ring gear.

The drive motor is expediently arranged between the tool holder and at least one of the rolling bodies, for example a planetary gear. This gives a suitable weight distribution.

In a preferred embodiment, the drive motor is arranged between the tool holder and at least one of the rolling bodies and/or the freewheel.

It is particularly preferred that the drive motor is arranged between the tool receiver and the positive rotation guide.

It is possible for the drive motor to drive the drive shaft directly. For example, the drive motor is a direct drive. In particular, the drive shaft is preferably provided or formed by a motor shaft of the drive motor. The drive shaft designed as a hollow shaft can be a motor shaft, for example.

However, it is also possible for the drive motor to drive the drive shaft indirectly, i.e. via a gear mechanism.

The gear mechanism may comprise or be an angle gear mechanism, in particular a bevel gear mechanism (Kegelradgetriebe), for example.

It is also possible for the gear mechanism to comprise or be a reduction gear mechanism (unterstetzungsgeitiebe) which reduces or increases the rotational speed of the drive motor. The gear mechanism may also be a switchable gear mechanism in which, for example, the first and second gear ratios are switchable. The gear mechanism is, for example, a multi-gear mechanism (mehrgantgatebe), in particular a two-gear mechanism.

The transmission may comprise or be a planetary transmission.

Preferably, the gear mechanism is switchable with respect to its direction of rotation. The gear mechanism can thus be switched, for example, in mutually opposite rotational directions, so that the drive shaft can be driven by the drive motor in different rotational directions with the same motor rotational direction of the drive motor. That is, the transmission mechanism causes the tool shaft to reverse from a first rotational direction to a second rotational direction and an opposite rotational direction.

Preferably, the drive shaft is arranged in an inner space of the drive motor. Even in this configuration, it is conceivable for the eccentric transmission and/or the variable-speed transmission to be arranged in the interior of the drive motor and for the drive motor to thereby drive the drive shaft by means of its motor shaft via the transmission.

It is particularly preferred that the drive shaft is formed by a motor shaft of a drive motor. The lamination stack can thus be arranged, for example, at the outer circumference of the drive shaft.

The drive motor is preferably electrically switchable between a first motor rotational direction and a second motor rotational direction opposite to the first motor rotational direction. In the case of rotation in the first motor rotation direction, the drive motor drives the drive shaft, for example, in such a rotation direction that the tool shaft rotates in the first rotation direction, while in the case of rotation in the second motor rotation direction, the drive motor drives the drive shaft in the opposite rotation direction, so that the tool shaft rotates in the second rotation direction. When the drive motor is a direct drive, the motor rotation direction is obviously equal to the rotation direction of the drive shaft. However, in the case of a transmission which switches between the drive motor and the drive shaft, a reversal in the direction of rotation can also occur in the drive train between the driven drive shaft of the eccentric transmission and the drive motor.

For switching the motor direction of rotation between the first motor direction of rotation and the second motor direction of rotation, an operating switch can be provided, for example, which can be brought into different switching positions. For example, a tumbler (Kippschalter) may be provided. However, it is also possible, for example, for a touch switch or other operating switches to be actuated in a predetermined switching sequence for switching the direction of rotation of the motor to be present. Thus, the touch switch can be switched, for example, by means of keys of different lengths, so that the touch switch or the current supply device actuates the drive motor for rotation in the first motor rotation direction or the second motor rotation direction.

Such an operating switch may be both an on and off switch for turning on and off the drive motor.

Preferably, a separate operating switch is associated with each motor direction of rotation, so that an operator can specifically adjust the motor direction of rotation by actuating the respective operating switch.

Preferably, the drive motor is an electronically commutated or brushless motor or a motor without an electromechanical rectifier. For the energization of the brushless or rectifier-free drive motor, the hand-held power tool has an energization device, by means of which the direction of rotation of the drive motor can be switched. The energized device has, for example, at least one half bridge.

A brushless or electronically commutated drive motor has the advantage that it has the same or substantially the same power in both directions of rotation. In electronically commutated or brushless motors, the efficiency is also the same or substantially the same in both rotational directions. Unlike the generic motors or brush motors which are likewise possible in principle and are also mentioned below, electronically commutated/brushless motors have the advantage that they can be operated optimally in mutually opposite motor directions of rotation. The optimal operating characteristics can be adjusted by means of software suitable for controlling the powered device. In particular, electronically commutated or brushless motors also have the advantage that they are free of wear, for example, at the commutator unit, irrespective of the direction of rotation. In the case of universal motors or motors equipped with commutators or brushes, the wear, for example caused by carbon or brushes, varies in magnitude depending on the respective direction of rotation.

Furthermore, in brushless motors, the direction of rotation can be switched significantly more easily. For this purpose, unlike in the case of universal motors or motors which operate with brushes, no complicated electromechanical components are required, by means of which components such as brushes or brushes have to be adjusted. The operator-operated electrical converter or sensor is sufficient to activate the control electronics or energization devices for the brushless motor in such a way that they change the motor direction of rotation.

However, the principle according to the invention can also be implemented by every other electric drive motor, i.e. also, for example, a so-called universal motor.

However, the drive motor may also be a pneumatic motor or a compressed air motor. In this case, the hand-held power tool advantageously has a corresponding valve assembly for adjusting the corresponding loading with compressed air.

The machine housing expediently has a handle for gripping by an operator. However, it is also possible for a handle element, in particular a rod-shaped handle element, to protrude from the machine housing, said handle element being connected to the machine housing via a hinge (Gelenk). For example, the hand-held power tool may be a top or wall burnisher.

Preferably, the drive motor is arranged in or at the machine housing. The eccentric drive can have a drive housing at which the at least one freewheel is supported. However, it is also possible for the machine housing, in particular the drive section of the machine housing, to form a gear housing for the eccentric gear.

A preferred embodiment provides that the positive rotation guide and/or the idle mechanism on the one hand and the tool holder on the other hand are arranged on mutually opposite sides of the machine housing, for example on the upper side and the lower side. In any case, it is advantageous if the positive rotation guide and/or the idle device is arranged in a protected region of the housing and beside the tool holder and thus the dish-shaped tool, so that the influence of dust, contaminants or the like is low.

Advantageously, the positive rotation guide or the idle device or both are arranged in the machine housing remote from the tool receptacle. In this case, the positive rotation guide and/or the idle device can be arranged at an end region of the tool shaft opposite the tool holder or the dish tool or at a wall region of the machine housing facing away from the tool holder or above. For example, it is provided that the idle device and/or the positive rotation guide are arranged below a cover wall above the machine housing.

An advantageous ventilation design can be designed as follows. A fan wheel, which can be driven directly or indirectly, for example by a drive motor, or else can be driven by a separate drive, is expediently arranged between the tool holder and one or more of the following components: a drive motor and/or a positive rotation guide and/or an idle device. For example, the following series arrangements are provided with respect to the longitudinal axis of the tool shaft and/or the drive shaft: a forced rotation guide and an idle device, a drive motor, a fan impeller, a tool receiving portion.

A suitable arrangement provides that the air flow generated by the fan wheel first flows through the drive motor, for example, before the air flow exits the housing or cools the forced-rotation guide or the idle rotation guide or both on the discharge side.

A cooling design in which a cooling air flow flows through the air guide assembly of the hand-held power tool in the direction of the tool holder at the forced rotation guide or the idle device or the drive motor or a combination thereof is preferred. A cooling air flow is drawn up next to the tool holder and thus the dish tool, where it is loaded with relatively little or no dust.

The machine housing of the hand-held power tool expediently has at least one inflow opening in a region facing away from the tool holder, for example at the handle section. The cooling air flows into the machine housing via inflow openings, for example respective grilles (giltter), and flows through one or more of the components explained below, namely the forced rotation guide, the idle device and the drive motor. The cooling air then expediently flows out at one or more outflow openings of the machine housing. However, it is also possible for the cooling air to flow out completely or partially in the region of the dish tool or the tool holder. Preferably, the cooling air or the cooling air flow exits the machine housing forward or directed forward in the working direction, so that the cooling air flow can flow into the region of the workpiece in front of the dish tool or the tool holder in the working direction, for example, in order to blow away dust.

Furthermore, it is advantageous, in particular, to arrange a partition wall in the machine housing between the tool holder and the positive rotation guide and/or the idle device and/or the drive motor, which partition wall separates the positive rotation guide, the idle device or the drive motor or a plurality thereof from the dust-loaded region of the hand-held power tool. Dust is generated by the disk tool during operation of the hand-held power tool, for example during the polishing of a workpiece. The partition walls may be said to form partition walls (schottky) or partition walls.

The partition wall can be formed or provided, for example, completely or partially by the fan wheel. The fan wheel is preferably arranged in the vicinity of the tool receptacle. The fan wheel can form a sort of base of the machine housing, for example, and thus a separating plane between the tool holder and the drive component, in particular the drive motor, the eccentric gear, the positive rotation guide or the like.

Between the fan wheel and the machine housing, a sealing arrangement, in particular a labyrinth seal (labyrinthdiching), is expediently provided.

In a preferred embodiment, the cooling air flow is sucked in by the fan wheel, as it were, via the drive component, in particular the drive motor and/or the forced rotation guide and/or the idle device, and is blown out of the machine housing in the region of the machine housing in the vicinity of the tool receptacle or in the vicinity of the dish tool. The fan wheel itself forms a partition or partition plane in turn in relation to the dust region of the hand-held power tool in which the tool holder or the disk tool is arranged. Dust air flows from the dust region, for example, via a dust discharge (Staubauslass) or a suction connection (Sauganschluss). A suction device (Saugger ä t) can be expediently coupled to the dust discharge.

It is obviously possible that the hand-held power tool can have a blower or the like for generating a dust air stream or for conveying dust-laden air away from the working area of the dish tool.

Furthermore, it is advantageous if the positive rotation guide and/or the freewheel device are arranged in a protected manner in a packaging housing (Kapselgeh ä use) or in a gear housing. The encapsulating housing or transmission housing is expediently a housing which is completely independent of the machine housing. However, it is also possible for the encapsulation housing or the gear housing to be formed at least partially by a machine housing, for example by an outer wall. The housing of the gear mechanism housing expediently has an opening, which is sealed by the bearing. The opening serves, for example, for receiving a drive shaft or a hollow shaft or a motor shaft or a tool shaft, wherein the respective shaft is expediently rotatably supported by means of a bearing with respect to the transmission housing or the encapsulation housing.

Drawings

Embodiments of the present invention are explained below with reference to the drawings. Wherein:

fig 1 shows a perspective oblique view of a hand-held power tool,

figure 2 shows a cross section through a front section of the hand-held power tool according to figure 1 approximately along section line a-a in figure 1,

fig. 3 shows a side view of the motor housing and the idler assembly of a variant of the hand-held power tool according to the preceding figures, wherein

A cross-sectional view along section line B-B in figure 3 is shown in figure 4,

figure 5 shows a cut through the idle assembly of the transmission in a neutral position approximately along the section line C-C in figure 3,

FIG. 6 shows the lost motion assembly according to FIG. 5 in the latched position

Fig. 7 shows the idle rotation assembly according to fig. 5 in an idle position, an

Fig. 8 shows a schematic further embodiment of the invention in a cross-sectional view.

Detailed Description

The hand-held power tool shown in the figures is preferably suitable for polishing and/or burnishing surfaces. The hand-held power tool is, for example, a sander 10.

The sander 10 has a machine housing 11 that can be comfortably grasped by an operator at a handle section 12. The handle section 12 protrudes from the drive section 13. At the drive section 13 a disk tool 14, for example a grinding disk 15, is arranged. The abrasive disc 15 may have a polishing means integrally or with a releasable polishing means 16 arranged at the lower side of the abrasive disc. The upper side 17 of the abrasive disc 15 faces the machine housing 11.

The grinding disc 15 or the disc tool 14 is located substantially below the cover 18 of the grinder 10, i.e. is covered from above. The cover 18 comprises a resilient sealing element 19, for example a sealing collar, which rests on the upper side 17 of the dish tool 14. That is, the cover 18 is arranged substantially dust-tight above the polishing disc 15 or at the polishing disc 15, so that dust originating from the working area of the polishing disc 15, i.e. in the area of the polishing means 16, can be drawn away, for example, by means of a suction channel 21 extending below the handle section 12. The suction channel 21 ends in a suction connection 22, to which, for example, a suction hose of a dust suction can be connected.

The switch 23 is expediently located on the side of the drive section 13 facing the handle section 12, by means of which the grinder 10 can be switched on and off. The switch 23 is, for example, a push switch (Druckschalter). By means of the switch 23, the energizing device 25 for energizing the drive motor 30 can be switched on or off. The direction of rotation of the drive motor 30 can be switched by means of the direction of rotation switch 24. The energization device 25 is responsible for energizing the drive motor 30 in the rotational direction adjusted accordingly by the rotational direction switch 24.

The energizing device 25 comprises, for example, a circuit with a half bridge (halbbrick), which is known per se. The drive motor 30 is expediently a brushless drive motor, in particular a commutatorless or electronically commutated drive motor. Of course, the drive motor 30 can also be a so-called universal motor, with a commutator or the like, without any problem. Furthermore, a compressed air motor or a pneumatic motor may also be used as the drive motor. In each case, it is advantageous if the direction of rotation of the drive motor 30 can be switched, for example, by corresponding energization by means of the energization device 25. In pneumatic or compressed air motors, the direction of rotation can be switched by applying compressed air correspondingly. In the case of drive motors with a commutator or a brush arrangement, the brush arrangement or the commutator can be adjusted, for example, for adjusting the direction of rotation of the drive motor.

The drive motor 30 has a stator 31 with a rotor 32 rotatably received in an inner space thereof. The drive motor 30 furthermore has an excitation coil arrangement 33 which is energized by the energizing device 25. The excitation coil assembly 33 is arranged on a lamination stack (Blechpaket)34, which achieves an optimal magnetic flux (sometimes also referred to as magnetic flux).

The rotor 32 is arranged on a drive shaft 35, i.e. a motor shaft. The drive motor 30 is a direct drive. However, this is not to be understood in this context as meaning that a drive design (antitriberbonzept) with a transmission (Ü bertragungsgetriebe), for example a bevel gear transmission and/or a transmission that changes the rotational speed (speed change transmission) or a transmission in which the rotational direction of the output drive of the transmission is switchable is not within the scope of the invention. This becomes more clear in connection with fig. 8.

The drive shaft 35 is designed as a hollow shaft 36. The drive shaft 35 is rotatably supported with respect to the machine housing 11 at

supports

37 and 38. The supports 37 and 38 are longitudinally spaced about the axis of rotation D about which the drive shaft 35 rotates.

The supports 37,38 are arranged, for example, at

support receptacles

46,47 of the stator body 45 of the drive motor 30. For example, the holding projection 48 of the carrier holder 70 projects in front of the stator body 45.

The drive motor 30 has a fan wheel 39, which is connected in a rotationally fixed manner to the drive shaft 35. For example, the fan wheel 39 is located next to the lower support 38 or at the longitudinal end region of the drive shaft 35 associated with the dish tool 14.

Hollow shaft 36 has an interior space H in which tool shaft 50 is rotatably received. A tool receptacle 51 for the disk tool 14 is provided at a longitudinal end 52a of the tool shaft 50. The longitudinal end 52a protrudes forward of the drive shaft 35. The tool receiver 51 has, for example, a bayonet profile and/or a screw thread and/or a plug receiver or similar other holding means for holding a disk tool. The disk tool 14 is fixed to the tool shaft 50, for example, by means of a threaded fastener 53.

At the tool shaft supports 42,44, which are spaced apart from one another about the drive axis D, the tool shaft 50 is rotatably supported at the drive shaft. The tool shaft bearings 42,44 are arranged, for example, in the bearing receptacles 41,43 in the interior H of the hollow shaft 36 or the drive shaft 35.

The tool shaft support 42 is, for example, a ball support. The tool shaft support 42 is arranged, for example, in the region of the longitudinal end 52 a.

In the region of the longitudinal end 52b opposite the longitudinal end 52a, the tool shaft 50 is supported by means of the tool shaft support 44 at the drive shaft 35. The tool shaft support 44 is, for example, a needle support (nadelager).

The tool shaft bearings 42,44 support the tool shaft 50 rotatably about the drive axis D, but not concentrically, but eccentrically with an eccentricity E. The tool rotation axis W of the tool shaft 50 has an eccentricity E with respect to the drive axis D.

Due to the friction of the tool shaft supports 42,44, the tool shaft 50 is carried along by the drive shaft 35 when the drive motor 30 puts the drive shaft 35 into rotation. In principle, the tool shaft 50 will reach the rotational speed of the drive shaft 35, but since the disc tool 14 is placed on the work piece, this causes a braking of the tool shaft. However, when the disk tool 14 is lifted from the workpiece, the rotational speed of the disk tool 14 is increased in an undesired manner without a brake acting on the disk tool 14 or the tool shaft 50, so that the disk tool 14 rotates at a high rotational speed when it is replaced on the workpiece, which leads to damage to the workpiece and/or premature wear of the disk tool 14 or the polishing means 16.

A braking means is thus provided in the form of, for example, a braking body 20, which is fixed in a stationary manner in relation to the machine housing 11, for example at the cover 18. The braking body 20 brakes the disc tool 14. The braking body 2013 acts, for example, on the upper side 15 of the grinding disk 15 or the disk tool 14. Alternatively or additionally, the elastic seal 19 or the cover 18 on the upper side 17 can also act in a braking manner on the upper side of the disk tool 14.

However, it is also possible for the hand-held power tool 10 to be designed such that the tool shaft 50 is set in a controlled manner in an eccentric rotary motion or a so-called hypocycloidal (hypocycloidal) motion, for which purpose a forced rotation guide 54 is provided. The positive rotation guide 54 comprises rolling

bodies

55,57 which are in a friction-fitting or form-fitting engagement with one another, so that, when the positive rotation guide 54 is activated, for example the rolling bodies 55 roll at the rolling bodies 57.

The rolling bodies 55 are, for example, toothed wheels 56 or central wheels which are arranged in the interior of a rolling body 57 designed as a ring gear 58 and roll on their inner circumference, for example, with intermeshing teeth.

The rolling bodies 55 are associated, for example, with the tool shaft 50. The rolling bodies 57 are associated with the machine housing 11 in contrast.

The rolling bodies 55 are connected in a rotationally fixed manner to the tool shaft 50.

The rolling bodies 57 can now be brought into engagement with the rolling bodies 55 or out of engagement with them, for example, on one side, in such a way that they are axially displaced, for example, along the drive axis D or the like. However, in order to make the action of the rolling elements 57 and thus of the forced rotation guide 54 ineffective, other embodiments are selected:

in order to bring the rolling bodies 57 out of function, the rolling bodies 57 are in principle rotatably mounted on the machine housing 11 by means of the bearing 61. When the rolling bodies 57 can be rotated relative to the machine housing 11 by means of the bearing 61, they are entrained by the other rolling bodies 55, i.e. the rolling bodies 55 cannot be set in rotation by rolling at the rolling bodies 57. That is, the rolling elements 55 can therefore also be freely rotated, as it were, in the machine housing 11 and likewise freely about the drive shaft 35 or about the drive axis a, so that there is a free-rotation eccentric mode already explained in which the brake means 20 is active, but the forced rotation guide 54 is not activated.

It is also possible for the support 61 to have such a braking torque that it brakes the rolling bodies 57 to such an extent that the rolling bodies 57 are not completely freely entrained by the rolling bodies 55, but rather a certain torque is transmitted from the rolling bodies 57 to the rolling bodies 55.

The support 61 is arranged, for example, externally at the outer circumference of the bearing projection 59 of the rolling body 57 and is held at the retaining body 70. The holding body 70 is fixed in position with respect to the machine housing 11. That is, the rolling elements 57 or the ring gear 58 are rotatably supported with respect to the machine housing 11 by means of the support 61. The holding body 70 has, for example, a holding projection 71, by means of which it is connected to the stator body 45, for example, engages in a receptacle of the stator body 45. A bearing receptacle 72 for the bearing 61 is also provided on the holder 70. The holding body 70 projects radially inwardly with a holding region 73 toward the axis of rotation D. The holding section 74 protrudes from the holding area 73.

The freewheel device 62 of the freewheel assembly 60 is connected to the holding section 74 and to the bearing projection 59 of the ring gear 58 or of the rolling body 57. Here, on the one hand, the radially outer idler part 63 of the idler device 62 is connected to the bearing projection 59, and on the other hand, the radially inner idler part 64 is connected to the retaining section 74. The

idle rotation members

63,64 are for example part of an idle rotation support 65. The

freewheel elements

63,64 are not rotatable relative to one another in the first direction of rotation D1 of the tool shaft 50, i.e. are supported relative to one another, so that the rolling bodies 57 are fixed in a rotationally fixed manner relative to the machine housing 11 via the freewheel device 62 and the retaining body 70. The other rolling elements 57 (planetary wheels) thereby roll within the ring gear 58, so that the other rolling elements are forced to perform a so-called hypocycloidal motion, so that the rotation guide 54 is forced to be active. The lost motion device 62 is in this case in its latched position.

The

freewheel elements

63,64 can rotate relative to one another in the second direction of rotation D2, so that the rolling bodies 57 are no longer supported with respect to the machine housing 11 and the rolling bodies 55 can entrain the rolling bodies 57, i.e. can rotate relatively freely in principle despite the bearing friction of the freewheel 62. In this case, the tool shaft 50 is itself freely carried along by the drive shaft 35, but is nevertheless braked by the brake body 20. This has already been explained. The direction of rotation D2 corresponds to the freewheeling direction of the freewheeling device 62. For example, the free-wheeling eccentric mode is active in the rotational direction D2.

That is, it is therefore possible to reverse by a simple turning direction of the drive motor 30, to switch between the forced rotation eccentric mode and the free rotation eccentric mode.

The rotational direction switch 24 may be operated, for example, to reverse the rotational direction of the drive motor 30. No costly mechanical handling elements are required. A simple electrical conversion is sufficient.

The operator can be signaled by the marking F for particularly fine workpiece machining, i.e. in this way the free-wheeling eccentric mode is adjustable. I.e. for example the flag F is associated with the direction of rotation D2. The operator is shown a coarser workpiece machining corresponding to the forced rotation eccentric mode and thus the direction of rotation D1 with the reference G. The markings F and G are arranged, for example, next to the rotary direction switch 24 or in connection with its two switching positions.

However, it is also possible to associate the two rotation directions D1 and D2 or the two eccentric modes, respectively, which are signaled by the symbols F and G, exclusively with the actuating switches 24a and 24 b. By pressing one of the two

operating switches

24a or 24b, the direction of rotation of the drive motor 30 can be switched and can thus be switched between the free-running eccentric mode and the forced-running eccentric mode by means of a simple push button (tastendlock).

It is also possible to cause an electrical direction of rotation of the drive motor 30 to be changed by a defined contact sequence (Tastenfolge), for example by a corresponding long or short actuation of the switch 30. Thus, for example, a switching sequence of two or three short presses of the switch 30 can be associated with the direction of rotation D1 and thus the forced rotation eccentric mode, while two or three long presses of the switch 30 with a predetermined pause are associated with the direction of rotation D2 and thus the free rotation eccentric mode.

The idle device 62 and the positive rotation guide 54 are arranged optimally in the hand-held power tool 10 with regard to cooling and less damage caused by dust and other contaminants. For example, the idle device 62 and the forced rotation guide 54 are arranged in a region of the machine housing 11 remote from the tool receptacle 51 and thus from the dish tool 14, preferably below the wall region 11 b. The wall region 11b is arranged, for example, on the housing upper side or above it at the drive section 13.

Further, the idle rotation device 62 and the forced rotation guide 54 are disposed in the packing case 80. The package housing 80 may also be referred to as a gear housing or gear housing. The encapsulating housing 80 has a lower partial housing 81 in the drawing and an upper partial housing 82 in the drawing, which receive the lost motion device 62 and the positive rotation guide 54 in the form of a housing (schalenartisg). The part of the encapsulation 80 facing the drive motor 30 or the sub-housing 81 is formed, for example, by the region of the stator body 45 facing away from the excitation coil arrangement 33 or the holding projection 48. The stator body 45 or the holding projection 48 or the sub-housing 81 is, for example, shell-shaped. The part of the encapsulation housing 80 which is further away from the drive motor 30 or the sub-housing 82 is provided by a retaining body 70 which covers the retaining projection 48 in the form of a cover or the receptacle provided by this for receiving the idle gear 62 and the positive rotation guide 54. The sub-housings 81,82 are screwed to each other, for example by means of one or more threaded fasteners 83. Preferably, the sub-housings 81,82 are interconnected with a stepped profile 84 and/or a labyrinth seal.

A resilient seal, such as an O-ring, may also be provided between the sub-housings 81 and 82.

The sub-housing 81 has a bearing receptacle 46 for the drive shaft 35/motor shaft bearing 37. The support 37 simultaneously seals the inner space of the encapsulating housing 80 against penetration of dust or the like. The support 37 forms a seal for the sub-housing 81 and thus the encapsulating housing 80.

Alternatively or additionally to the embodiment in which the dust encapsulating housing 80 encapsulates the idle device 82 and the positive rotation guide 54 relative to dust, the following-mentioned embodiment of dust isolation is advantageous.

The region of the machine housing 11 facing the dish tool 14 and below in the drawing can be said to be a dust region which communicates with the suction channel 21. Thus, the forcible rotation guide 54 and the idle rotation member 60 are not only spatially separated but also separated by the partition wall 90.

The partition wall 90 is, as it were, stationary, but rotatable, with respect to the longitudinal axis of the drive shaft 35. I.e. the partition wall is provided by the base wall or foundation wall of the fan wheel 39. A seal assembly 91 is provided between the outer periphery of the fan impeller 90 and the machine housing 11. The seal assembly 91 includes, for example, a labyrinth seal 92.

On the side of the fan wheel 90 facing the disk tool 14, a suction space 96 is provided, which communicates with the suction channel 21. When the dust air S is drawn off via the extraction channel 21, a lower pressure prevails in the extraction space 96 than in the region of the fan wheel 39 facing away from the extraction space 96 and facing the drive motor 30, so that the dust air S does not flow into the region of the drive motor 30 and ultimately into the region of the forced rotation guide 54 and the idle running assembly 60, but rather flows in the direction of the extraction space 96 in each case from this region, which can be said to be cleaner, or the fresh air region. Thereby, the dust load of the driving motor 30 and the forced rotation guide 54 and the idle rotation assembly 60 is low.

The dust air S can flow, for example, through the passage opening 96 at the polishing disk 15 or the disk tool 14 in the direction of the removal channel 21 in the region 94 between the cover 18 and the polishing disk 15. The cover 18 itself has a through-opening 95, so that dust air S can flow from the region 94 into the extraction space 96 and finally into the extraction channel 21.

Furthermore, the cooling design of the hand-held power tool 10 explained below optimally helps to optimally cool the drive motor 30 and/or the idle running assembly 60 and/or the positive rotation guide 54 and to be loaded in particular by dust in a particularly free or low manner.

The cooling air flow K is generated by the rotation of the fan wheel 39. The cooling air flow K flows into the machine housing 11 via an inflow opening 97, preferably at the handle section 12 or in any case at a section of the machine housing 11 remote from the tool receptacle 51, flows through the machine housing 11, and flows out at an outflow opening 98. The outflow opening 98 is preferably arranged at the drive section 13. Thereby, the cooling air flow K preferably flows through the energized device 25 in order to cool the energized device. Furthermore, the cooling air flow K flows through the idle running assembly 60 or the idle running device 62 and cools the idle running assembly or the idle running device and the forced rotation guide. The cooling air flow K then flows through the drive motor 30 and in particular through the excitation coil assembly 33, so that the drive motor 30 is also optimally cooled. The cooling air K heated in this way overall then flows out of the machine housing 11 laterally, preferably in the forward direction in the working direction as shown in fig. 1. I.e. the cooling air K is thus sucked up beside the working area of the disk tool 14, where the dust load is low. The cooling air K then flows in the direction of the disk tool 14, so that it can preferably still contribute to the working area of the disk tool 14 or the area X which is disposed forward in the working direction in front of the working area of the disk tool 14 being protected from loads, for example from dust or other dirt.

In the hand-held power tool 110, which is only partially shown in fig. 3 to 7, there are essentially the same components (Bauteile) as in the hand-held power tool 10 already described, in particular the drive motor 30, which is designed as a direct drive. The drive motor 30 is not or only schematically shown, as is its drive shaft 35, however the tool shaft 50 is shown arranged in the drive shaft 35 and driven by the drive shaft 35. At the upper longitudinal end region of the tool shaft 50, rolling bodies 55 are provided, which are designed, for example, as planetary wheels and which, when the idler assembly 160 with the idler device 162 is in its locked position, can in principle roll on the rolling bodies 57 designed as ring gears 58. When the idle device 162 occupies its idle position, the rolling bodies 55 can entrain the rolling bodies 57. The associated directions of rotation D1 and D2 of the tool shaft 50 are shown in fig. 6 and 7.

The drive motor 30 is arranged, for example, in the motor housing 145, for example, in an inner space of the motor housing 145 limited by the peripheral wall 147. The drive shaft or motor shaft of the drive motor 30, which is not visible in the figures, is supported, for example, by the already explained bearing 37, which is in turn accommodated in a bearing receptacle 146 of the motor housing 145.

At the end side or end wall 149A facing the idle device 162, the motor housing 145 has a number of a plurality of through openings 149 for cooling air for cooling the drive motor 35.

A retaining projection 148 projects forward of the end wall or end side 149A, which serves to retain a retaining body 170. The holding body 170 serves in principle to hold the idle mechanism 160 in a stationary manner with respect to the machine housing 11 and also to hold a bearing arrangement with bearings 161 for the rotatable mounting of the rolling bodies 57. The holding body 170 is provided with, for example, a holding projection 171, which is connected to the holding projection 148 of the motor housing 145. For example, the corresponding plug receptacle and plug projection engage with each other.

The holding projection 171 projects from the holding region 173 in the direction of the rotation axis D, for example. The retaining region 173 is designed, for example, in the form of an end wall. A bearing receptacle 174 for the bearing 161 is provided, for example, at the holding region 173.

A support projection 159, at the radially outer periphery of which a bearing 161 is provided, projects in front of the rolling bodies 57 with respect to the axis of rotation D. The support projection 159 is designed, for example, in the form of a pin (Zapfen) or a sleeve.

The bearing 161 is arranged between a holding region 173 of the holding body 170, which is fixed in position with respect to the machine housing 11, in particular the bearing receptacle 174 and the bearing projection 159.

Furthermore, between the two components bearing receptacle 174 and bearing projection 159, an idler device 162 is provided, which has an idler part 163 and an idler part 164 connected to the ring gear 58 or rolling body 57, which idler part 164 is fixed in a positionally fixed manner in relation to the machine housing 11, i.e. in relation to the holding body 170, in a locking direction corresponding to the rotational direction D1, and in the rotational direction D2 assumes an idler position in which the idler part 164 and thus the rolling body 57 can rotate relative to the machine housing 11.

The retention tab 148 forms a sub-housing 181 of the package housing 180, and the retention body 170 forms a sub-housing 182 of the package housing 180. The packing case 180 receives the forcible rotation guide 54. The sub-housings 181,182 are intermeshed with a stepped profile or labyrinth seal 183.

The bearing 137 seals an opening of the sub-housing 181 through which the driving shaft of the driving motor 30 penetrates into the packing housing 180 and rotatably supports the driving shaft 35 of the driving motor 30. The support 161 is expediently completely or at least partially covered by a cover wall (deckwind) 184 of the sub-housing 182 or the encapsulating housing 180.

The encapsulating housing 180 and thus the idle rotation assembly 160 and the positive rotation guide 54 are also arranged in the upper region of the machine housing 11, in any case away from the dish tool 14. Thereby reducing or avoiding the effects or contamination due to dust.

An intermediate space 169 is provided between the idle rotation part 163 and the idle rotation part 164, in which a number of blocking bodies 165, for example rotation blocking bodies 165, are movably accommodated. The blocking body 165 can be moved, for example rolled, in the intermediate space 169 about the axis of rotation D. The blocking body 165 is expediently a ball, a roller or the like.

The blocking body 165 is accommodated in the entrainment recess 166 provided at the outer periphery of the idle rotation member 163 in the rotational direction D2 (the idle rotation direction of the idle rotation device 162) corresponding to the free rotation eccentric mode. The entrainment recess 166 is so deep that the blocking body 165 does not cause jamming or blocking of the lost motion components 163,164 relative to one another. The distance of the bottom of the corresponding entrainment recess 166 relative to the inner circumference of the idle rotation member 164 is greater than the diameter of the stopper 165.

For example, in addition to the entraining recess 166, a entraining projection 166a is provided, which is provided for entraining the rotation of the blocking body 165 in the direction of rotation D2 and thus takes care that the blocking body 165 reaches into the entraining recess 166 in the direction of rotation D2. When the blocking body 165 is in the driving recess 166, it no longer bears against the radially inner periphery of the idle part 164, so that the idle parts 163,164 can rotate relative to one another. That is, the idle rotation member 163 and thus the rolling bodies 57 can rotate with respect to the machine housing 11.

In contrast, the blocking body 165 is cambering out (austaughen) of the entrainment recess 166 in the direction of rotation D1, for example, by means of which it can be thrown or expelled radially outward from the entrainment recess 166 as a result of centrifugal force. Then, the stopper reaches a wedge-shaped inclined portion or a stopper inclined portion 168 provided, for example, at the back side of the entraining protrusion 166 a. The wedge-shaped inclined portion 168 has such a small distance from the inner periphery of the idle running part 164 that the blocking body 165 is jammed between the wedge-shaped inclined portion 168 and the inner periphery of the idle running part 166, so that the idle running part 163 is blocked, i.e. takes up its blocking position, with respect to the idle running part 164. As a result, the ring gear 58 or the rolling bodies 57 can no longer rotate, so that the other rolling bodies 55 roll on the inner circumference of the rolling bodies 57, and are finally set to the forced-rotation eccentric mode.

In this case, the changeover between the different eccentric modes can also be effected comfortably by a simple reversal of the direction of rotation of the drive motor 35.

In the exemplary embodiment according to fig. 8, a drive motor 230, for example a universal motor, a brushless motor, a pneumatic motor or the like, is arranged in the machine housing 211, which drives a drive shaft 235 via a gear mechanism assembly or gear mechanism 280. The gear mechanism assembly comprises, for example, a gear mechanism 281 and/or a switching gear mechanism 284 for reversing the direction of rotation and/or an angle gear mechanism 287. This gives a drive train which can be said to be complex, which can obviously also be designed simply. In general, for example, an integrated transmission with one or more functions can also be provided, in which case the functions of, for example, the variable speed transmission and the angle transmission are implemented by a transmission structural unit.

That is, the follower of the drive motor 230 first drives the speed change transmission mechanism 281. For example, a first transmission stage and a second transmission stage which exhibit different transmission ratios can be switched by means of the actuating element 282. The actuating element 282 projects, for example, in front of the machine housing 211.

The follower 283 of the shift transmission mechanism 281 drives the rotational direction transmission mechanism or the switching transmission mechanism 284. By means of a switching gear 284 which can be actuated via an actuating element 285, the direction of rotation of a drive output 286 of the switching gear 284 can be switched, for example. Thereby, the switching between the first and second rotation directions of the driving shaft 235 is possible with the same rotation direction of the driving motor 230.

The drive motor 230 can be arranged, for example, in a handle section of the machine housing 211, likewise in the handle section 12, which is simplified and not shown in the figures. In any case, the axial direction of the drive motor 230 is at an angle, e.g., a right angle, relative to the axial direction of the drive shaft 235. A corresponding force transmission takes place between the drive motor 230 and the drive shaft 235 by means of an angle drive 287, for example a bevel gear drive. In this position, it is to be noted that, for example, the angle drive 287 can also have a transmission ratio between the drive motor 230 and its output which is coupled to the drive shaft 235 or forms the drive shaft 235.

The drive shaft 235 is recessed into the interior of a tool shaft 250, which is designed as a hollow shaft 236. The tool shaft 255 is rotatably supported at the drive shaft 235, for example, via tool shaft supports 242 and 244 spaced apart from each other about the rotational axis D of the drive shaft 235. In a manner not shown in greater detail, the already explained disk tool 14, i.e. for example a polishing disk 15 or a polishing disk with a polishing or grinding means 16, is arranged at the free end region of the tool shaft 250 via the tool holder 51. In any event, the drive shaft 235 drives the tool shaft 250 in principle via the bearing friction of the

tool shaft bearings

242, 244.

The axis of rotation W of the tool shaft 250 and the axis of rotation D of the drive shaft 235 have an eccentricity E, which in turn implements an eccentric transmission 240. For braking the disk tool 14 in the free-wheeling eccentric mode, a braking device with a braking body 20 is provided, which is schematically illustrated.

To illustrate the different variants of the invention, idle assemblies 260,360 are provided, which are explained below. For example, the rolling bodies 255 of the forced rotation guide 254 are connected to the tool shaft 250 via the idle running device 262. When the freewheel device 262 assumes its locking direction, the rolling bodies 255, for example planetary wheels, can roll on the inner circumference of the rolling bodies 257, which are designed as hollow wheels and are fixed in position with respect to the machine housing 211. The rolling bodies 257 are arranged, for example, on retaining projections 248 which project radially inward in front of the side walls 249 of the machine housing 211 toward the tool shaft 235.

The lost motion device 262 is only schematically shown. The freewheel devices have, for example, freewheel elements 263,264 which are not rotatable relative to one another in the direction of rotation D1, i.e. take up a blocking position, and which are rotatable relative to one another in the direction of rotation D2 of the drive shaft 235. That is, the lost motion device 262 is in lost motion in the rotational direction D2. And then adjusted to a free-wheeling eccentric mode. The operator achieves this change completely simply by switching the switching gear 284 between the two rotational directions D1 and D2. Although a mechanical changeover between the eccentric modes is required, the considerable advantage results that the switching mechanism does not have to be located directly in the region of the tool or drive shaft, but rather is ergonomically suitable, for example, at the handle, where a change in the direction of rotation can take place by means of the actuating element 282.

In the above embodiments, the ring gear is associated with the machine housing and the planet gear is associated with the tool shaft, respectively. The reverse arrangement is possible, however, as indicated in the lost motion device 362 of the lost motion assembly 360. In this case, the rolling bodies 355 associated with the tool shaft 250 are designed as hollow wheels, for example, and when the forced rotation guide 354 is active, the rolling bodies 357 (so-to-speak planet wheels) can roll at the radially inner peripheries of the rolling bodies 355. For example, the idle member 363 of the idle device 362 is connected with the rolling bodies 355, and the idle member 364 is connected with the tool shaft 250.

The planet wheels or rolling bodies 357 can in principle likewise be connected to the machine housing 211 via a freewheel device, for example by means of a freewheel device 462. The freewheel device 462 can, for example, effect a free rotation of the rolling bodies 357 relative to the machine housing 211 in the direction of rotation D2. It is also possible that the freewheel device 462 in the freewheel position or in the direction of rotation D2, although essentially achieving a rotatability of the rolling elements 357 relative to the machine housing, nevertheless has a certain resistance or viscosity (Z ä highkeit, sometimes also referred to as toughness or rigidity). For example, the freewheeling device 462 contains a fluid, for example oil, which in the freewheeling position, although a relative rotatability of the freewheeling components of the freewheeling device 462 is achieved, nevertheless has a braking torque or has a rotational resistance. The forced guide 354 is thus not activated on a full scale, but nevertheless exerts a certain hypocycloidal torque in the idle position of the idle device 462 of the tool shaft 250.

Advantageously, however, the rolling bodies 357 are arranged fixedly at a retaining projection 348, which projects for example in front of a peripheral wall of the machine housing 211. The

idle members

363 and 364 cannot rotate relative to each other in the direction of rotation D1, so the ring or rolling bodies 355 roll at the outer periphery of the rolling bodies 357. For example, friction surfaces or similar teeth are provided between the rolling

elements

355 and 357. In contrast, the freewheeling

segments

363 and 364 can rotate relative to one another in the direction of rotation D2, so that the rolling elements 355 remain stationary, so to speak, with respect to the machine housing 211. That is, in this case, the tool shaft 250 rotates freely with respect to the machine housing 211 except for the brake generated by the brake body 20.

The partition wall 290, which is fixed in position with respect to the machine housing and is penetrated only by the hollow shaft 236, separates the extraction space 296, which faces the dish tool 14 and is in flow connection with the extraction channel 21, from the region of the machine housing 211 in which, for example, the drive motor 230 and/or the positive rotation guide 354,254 and the idle gear associated therewith are arranged in the hand-held power tool 210. The suction space 296 can be suctioned via the already illustrated suction channel 21 and the suction connection 22. The dust air S can flow into the suction space 296 via the inflow opening 93 at the disk tool 14.

Claims

1. A hand-held power tool having an eccentric gear (40) arranged in a machine housing (11) and an electric or pneumatic drive motor (30) for rotationally driving a drive shaft (35) of the eccentric gear (40) about a drive axis (A), wherein the eccentric gear (40) has a tool shaft (50) which, for performing an eccentric movement, is eccentrically rotatably mounted on the drive shaft (35) by means of at least one tool shaft bearing (42,44) and has a tool receptacle (51) for a disk tool (14), wherein a forced rotation guide (54) is provided which, in a forced rotation eccentric mode of the tool shaft (50), is guided by one rolling element (55,57) of the forced rotation guide (54) in a further rolling element (55) of the forced rotation guide (54), 57) -rolling forcing a rotational movement with respect to the machine housing (11), wherein one of the rolling bodies (55,57) is supported at the machine housing (11) and the other of the rolling bodies (55,57) is supported at the tool shaft (50), characterized in that between at least one of the rolling bodies (55,57) and the tool shaft (50) or the machine housing (11) there is arranged a lost motion device (62) having at least one rolling body supported at the machine housing (11) or the tool shaft (50) in a first rotational direction of the tool shaft (50) corresponding to a latching direction of the lost motion device (62) by a support force adapted for the rolling of the other rolling body, such that one rolling body supported at the tool shaft (50) can roll at the other rolling body supported at the machine housing (11), and is rotatably releasable in a second direction of rotation of the tool shaft (50) corresponding to the direction of idle rotation of the idle device (62) in order to allow the tool shaft (50) to rotate relative to the machine housing (11) without the rolling bodies (55,57) rotating relative to one another, wherein the drive motor (30) is arranged between the tool receptacle (51) and at least one of the rolling bodies (55,57) and/or the idle device (62) and/or the positive rotation guide (54).

2. Hand-held power tool according to claim 1, characterised in that one of the rolling bodies (55,57) is a planet wheel and the other of the rolling bodies (55,57) is a hollow wheel (58) which accommodates the planet wheel.

3. Hand-held power tool according to claim 2, characterised in that the hollow wheel (58) is associated with the machine housing (11) and the planet wheel is associated with the tool shaft (50).

4. Hand-held power tool according to one of the preceding claims, characterized in that the rolling bodies have teeth or are gear bodies or that there is a friction fit between the rolling bodies.

5. Hand-held power tool according to claim 1, characterized in that only one of the rolling bodies (55,57) is supported by means of one idle device (62) with respect to the tool shaft (50) or the machine housing (11), or both rolling bodies (55,57) are supported by means of one idle device (62) with respect to the tool shaft (50) or the machine housing (11), respectively.

6. Hand-held power tool according to claim 1, characterized in that at least one idle device (62) forms an integral part of or is arranged at a support (65) by means of which the rolling bodies (55,57) are rotatably supported with respect to the machine housing (11) or the tool shaft (50).

7. Hand-held power tool according to claim 6, characterised in that the support (65) is a rolling support.

8. Hand-held power tool according to claim 6, characterized in that the at least one idle device (62) has rolling bodies (55,57) supported there locked or blocked in a locked position with respect to rotation relative to a component supporting the idle device (62), the machine housing (11) or the tool shaft (50).

9. Hand-held power tool according to claim 1, characterised in that the tool shaft (50) is eccentrically accommodated in the drive shaft (35).

10. The hand-held power tool according to claim 1, characterized in that the drive shaft (35) has a hollow shaft (36) or is designed as a hollow shaft (36), in which the tool shaft (50) is arranged.

11. Hand-held power tool according to claim 1, characterised in that the tool shaft (50) projects in front of the drive shaft (35) at a region facing away from the tool receptacle (51) and carries one of the rolling bodies (55, 57).

12. Hand-held power tool according to claim 1, characterised in that the drive motor (30) is a brushless and/or electronically commutated motor.

13. The hand-held power tool according to claim 1, characterized in that the drive shaft (35) is formed by a motor shaft of the drive motor (30) and/or the drive motor (30) directly drives the drive shaft (35).

14. The hand-held power tool according to claim 1, characterized in that a switchable gear mechanism (284) and/or an angle gear mechanism (287) and/or a gear mechanism (281) is/are arranged between the drive motor (30) and the drive shaft (35).

15. The hand-held power tool according to claim 1, characterized in that the drive shaft (35) is arranged in an interior space of the drive motor (30).

16. Hand-held power tool according to claim 1, characterised in that the tool shaft (50) and the drive shaft (35) rotate in the same direction.

17. Hand-held power tool according to claim 1, characterised in that the drive motor (30) is electrically switched between a first motor rotational direction and a second motor rotational direction opposite to the first motor rotational direction.

18. Hand-held power tool according to claim 17, characterised in that the hand-held power tool has, for switching the motor direction of rotation, switches which are actuated in a predetermined switching sequence or operating switches (24) which are brought into different switching positions or actuating switches (24a,24b) which are respectively associated with the first motor direction of rotation and the second motor direction of rotation.

19. The hand-held power tool according to claim 1, characterized in that the tool shaft (50) is in a free-rotating eccentric mode in the second rotational direction, in which free-rotating eccentric mode the tool shaft (50) performs a rotational movement upon rotation of the drive shaft (35) on the basis of a bearing friction of the at least one tool shaft bearing (42,44) and is freely rotatably movable about the drive axis (a).

20. The hand-held power tool according to claim 1, characterized in that the positive rotation guide (54) and/or the idle device (62) are arranged at one side of the machine housing (11) and the tool receptacle (51) is arranged at the opposite side of the machine housing (11).

21. The hand-held power tool according to claim 1, characterized in that the positive rotation guide (54) and/or the idle device (62) are arranged at an end region of the tool shaft (50) opposite the tool receptacle (51) and/or at a wall region (11b) of the machine housing (11) facing away from the tool receptacle (51) and/or outside a dust air flow (S) flowing away from a working region of the dish tool (14).

22. Hand-held power tool according to claim 1, characterised in that the positive rotation guide (54) and/or the idle device (62) are arranged in a completely or substantially closed encapsulating housing (80).

23. The hand-held power tool according to claim 22, characterized in that at least one opening of the encapsulation housing (80) is sealed by a bearing (37) and/or the encapsulation housing (80) has a sub-housing (81,82) which accommodates the positive rotation guide (54) and/or the idle device (62) in the manner of a shell.

24. The hand-held power tool according to claim 1, characterized in that a fan wheel (39) is arranged between the tool receptacle (51) and the drive motor (30) and/or between the tool receptacle (51) and the positive rotation guide and/or between the tool receptacle (51) and the idle gear (62).

25. The hand-held power tool according to claim 1, characterized in that a separating wall (90) is arranged between the tool holder (51) and one of the group consisting of the forced rotation guide (54), the idle device (62) and the drive motor (30), which separating the forced rotation guide (54) or the idle device (62) or the drive motor (30) from a dust-laden region or a removal space (96) of the hand-held power tool, wherein the dust is generated by the disk tool (14) during operation of the hand-held power tool.

26. Hand-held power tool according to claim 25, characterized in that the partition wall (90) is provided or formed at least partially or completely by a fan wheel (39).

27. The hand-held power tool according to claim 26, characterized in that a seal (92) is provided between an edge region of the fan wheel (39) and the machine housing (11).

28. The hand-held power tool according to claim 1, characterized in that it has an air guide assembly for guiding a cooling air flow (K) in the direction of the tool receptacle (51) past the positive rotation guide (54) and/or the idle device (62) and/or the drive motor (30).

29. The hand-held power tool according to claim 1, characterized in that the machine housing (11) has at least one inflow opening (97) in a region facing away from the tool receptacle (51), into which inflow opening a cooling air flow (K) flows into the machine housing (11) when the hand-held power tool is in operation, flows past the positive rotation guide (54) and/or the idle device (62) and/or the drive motor (30) and out of the machine housing (11).

30. The hand-held power tool according to claim 1, characterized in that the hand-held power tool is a sander (10) and/or a polishing machine.

31. The hand-held power tool according to claim 1, characterized in that the disk-type tool (14) is an abrasive disk (15) or a polishing disk.

32. The hand-held power tool according to claim 1, characterized in that the idle device (62) couples the at least one rolling body (55,57) in a rotationally fixed manner at the machine housing (11) or the tool shaft (50) in a first rotational direction of the tool shaft (50) by means of a bearing force which is suitable for the rolling of the further rolling body (55, 57).

33. Hand-held power tool according to claim 7, characterized in that the rolling bearing is a ball bearing.

34. Hand-held power tool according to claim 14, characterised in that the switchable gear mechanism (284) is switchable with respect to its direction of rotation and/or its transmission ratio.

35. Hand-held power tool according to claim 17, characterised in that the drive motor (30) is electronically switched between the first motor rotational direction and the second motor rotational direction which is opposite with respect to the first motor rotational direction.

36. Hand-held power tool according to claim 19, characterised in that it has braking means for braking the tool shaft (50) or the tool in the free-wheeling eccentric mode.

37. Hand-held power tool according to claim 20, characterised in that the opposite sides are an upper side and a lower side of the machine housing (11).

38. The hand-held power tool according to claim 24, characterized in that the fan wheel (39) is driven directly or indirectly by the drive motor (30).

39. The hand-held power tool according to claim 25, characterized in that the partition wall (90) is arranged in the machine housing (11).

40. The hand-held power tool according to claim 27, wherein the seal (92) is a labyrinth seal.

41. The hand-held power tool according to claim 29, wherein the region facing away from the tool receptacle (51) is at a handle section (12).

42. The hand-held power tool according to claim 29, characterized in that the cooling air flow (K) flows out of the machine housing (11) via at least one outflow opening (98) of the machine housing (11).