Abstract:
The invention relates to a hand-held machine tool, in particular a hammer drill and/or chipping hammer. The tool according to the invention has a transmission device with a drive bearing that has at least one torque-transmitting means with a transmitting contour for transmitting a torque onto the drive bearing. According to the invention, the transmitting contour of the torque-transmitting means is produced by axial machining and/or a stamping and/or planning process.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a 35 USC 371 application of PCT/EP2008/051408 filed on Feb. 5, 2008. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is based on a hand-held power tool 
     2. Description of the Prior Art 
     There is already a known hand-held power tool that has a transmission device equipped with a drive end bearing. The drive end bearing has a torque transmitting element with a transmitting contour for transmitting a torque to the drive end bearing. 
     ADVANTAGES AND SUMMARY OF THE INVENTION 
     The invention is based on a hand-held power tool, in particular a rotary hammer and/or a hammer chisel, having a transmission device equipped with a drive end bearing that has at least one torque transmitting element with a transmitting contour for transmitting a torque to the drive end bearing. 
     According to one proposed embodiment, the transmitting contour of the torque transmitting element is manufactured by means of an axial machining and/or a stamping process and/or a milling process, advantageously making it possible to achieve an inexpensive manufacture with a particularly short manufacturing time for the transmitting contour of the torque transmitting element. In this connection, the expression “axial machining” is understood to mean a production process in which a machining occurs at least essentially, and advantageously exclusively, by means of a translatory relative movement in at least one axial direction between a component, in particular the torque transmitting element, and a tool; preferably no relative rotational movement or at least no significant relative rotational movement occurs between the torque transmitting element and the machining tool. The drive end bearing is preferably provided together with a wobble drive in order to convert a rotating motion of a shaft, e.g. an intermediate shaft, into an axial reciprocating motion in order to produce an axial hammering pulse. 
     According to another proposed embodiment, the torque transmitting element is of one piece with the drive end bearing, thus permitting savings of additional parts, space, assembly complexity, and costs. The expression “of one piece with” here is understood in particular to mean embodied of one piece and/or that the drive end bearing and the torque transmitting element comprise a single component that is produced from a single piece. 
     An advantageous torque transmission with a simultaneous support of the torque transmitting element on an axle or shaft such as an intermediate shaft of the transmission device, can be achieved if the transmitting contour is situated on a radially outward-oriented surface of the torque transmitting element. It is also conceivable, however, to situate the torque transmitting contour on a radially inward-oriented surface and/or on an end surface of the torque transmitting element. 
     According to another proposed embodiment of the invention, the transmitting contour has at least two transmitting elements that are situated spaced uniformly apart from each other in a circumference direction of the torque transmitting element, thus in particular enabling a uniform transmission of torque from another component to the torque transmitting element. 
     If the hand-held power tool also includes a transmission element on which the torque transmitting element is rotatably supported, then this enables achievement of an inexpensive, part-saving support on an already existing component, i.e. the transmission element, that is required for the function of the transmission device. The transmission element is preferably constituted by an axle and/or particularly advantageously, by a shaft such as an intermediate shaft. 
     According to an advantageous proposed modification, the torque transmitting element has at least one stamped relief groove, enabling a structurally simple manufacture to be achieved by means of a stamping process. In this connection, it is particularly advantageous if the stamped relief groove is situated on a side of the torque transmitting element oriented toward the drive end bearing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings, in which: 
         FIG. 1  is a side view of a hand-held power tool according to the invention, embodied in the form of a rotary hammer, 
         FIG. 2  is a side view of a transmission device of the hand-held power tool, 
         FIG. 3  is a side view of a drive end bearing of the transmission device, and 
         FIG. 4  is a perspective view of the drive end bearing from  FIG. 3 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a hand-held power tool  10  embodied in the form of a rotary hammer. The hand-held power tool  10  includes a housing  34  and, in a front region, a tool holder  36  for holding a tool. At an end oriented away from the front region, the hand-held power tool  10  has a main handle  38  for actuating the hand-held power tool  10  and for transmitting force from an operator to the hand-held power tool  10 . The hand-held power tool  10  has a drive unit  40  comprised of an electric motor to produce a drive moment. The torque of the drive unit  40 , in the form of a drive moment, is transmitted via a transmission device  12  of the hand-held power tool to a pneumatic impact mechanism  42 , which is only partially shown for the sake of visibility, and/or to a rotating output element constituted by a hammer tube  44  ( FIG. 2 ). 
       FIG. 2  shows a subregion of the handheld power tool  10  with the transmission device  12 . The transmission device  12  has a transmission element  28  composed of an intermediate shaft  46  via which the torque of the drive unit  40  is transmitted to the impact mechanism  42  and the hammer tube  44  during operation of the hand-held power tool  10 . To this end, a drive end bearing  14  and a gear unit  48  of the transmission device  12  are supported on the intermediate shaft  46 . During operation of the hand-held power tool  10 , the drive end bearing  14  converts a rotating motion of the intermediate shaft  46  into an axial motion to generate a hammering pulse and transmits this motion to the impact mechanism  42 . The gear unit  48  serves to transmit the torque from the intermediate shaft  46  to the hammer tube  44  or more precisely, to a gear  50  that is coupled to the hammer tube for co-rotation. 
     To permit a transmission of torque to the drive end bearing  14 , the drive end bearing  14  has a torque transmitting element  16  with a transmitting contour  18 . The drive end bearing  14  and the torque transmitting element  16  are embodied of one piece with each other and are rotatably supported on the intermediate shaft  46 . The torque transmitting element  16  is situated along the force flow direction  56  of the intermediate shaft  46  at an output end  62  of the drive end bearing  14 . The drive end bearing  14  also has a bearing sleeve  52  and a wobble pin  54 , with the wobble pin  54  supported on the bearing sleeve  52 . When the bearing sleeve  52  is rotated around a rotation axis  78  of the intermediate shaft  46 , the wobble pin  54  executes a reciprocating motion along the force flow direction  56 . The drive end bearing  14  is supported with its drive unit end  58  resting against an intermediate flange  60  of the hand-held power tool  10  ( FIGS. 2 through 4 ). 
     The transmitting contour  18  of the torque transmitting element  16  has four transmitting elements  22 ,  24 ,  64 ,  66  that are situated on a radially outward-oriented surface  20  of the torque transmitting element  16 . In addition, the four transmitting elements  22 ,  24 ,  64 ,  66  of the torque transmitting element  16  are situated spaced uniformly apart from one another in a circumference direction  26  constituted by a rotation direction of the torque transmitting element  16  ( FIGS. 3 and 4 ). The transmitting contour  18  of the torque transmitting element  16  is manufactured by means of a stamping process with an axial machining. To this end, the torque transmitting element  16  has a stamped relief groove  30  on a side  32  oriented toward the drive end bearing  14 . The stamped relief groove  30  here has a smaller diameter  70  than an addendum circle diameter  68  of the torque transmitting element  16  ( FIGS. 3 and 4 ). 
     During operation of the hand-held power tool  10 , the torque of the intermediate shaft  46  is transmitted via a torque transmitting element  72  of the intermediate shaft  46  to the torque transmitting element  16  of the drive end bearing  14  and from thence to the drive end bearing  14 . The torque transmitting element  72  of the intermediate shaft  46  in this case has a transmitting contour  74  identical to the transmitting contour  18  of the torque transmitting element  16  of the drive end bearing  14 . In addition, the torque transmitting element  72  of the intermediate shaft  46  is affixed to the intermediate shaft  46  for co-rotation and is situated after the torque transmitting element  16  of the drive end bearing  14  in the force flow direction  56  ( FIGS. 2 and 3 ). 
     A transmitting sleeve  76  is supported on the torque transmitting element  16  of the drive end bearing  14  and on the torque transmitting element  72  of the intermediate shaft  46  and is able to slide both in the force flow direction  56  and counter to the force flow direction  56  ( FIG. 2 ). To this end, the transmitting sleeve  76  has an inner contour, not shown in detail, which corresponds to the transmitting contours  18 ,  74  of the two torque transmitting elements  16 ,  72 . During operation of the hand-held power tool  10 , the torque transmission from the intermediate shaft  46  to the drive end bearing  14  can be switched on and off by means of the transmitting sleeve  76 . If the transmitting sleeve  76  is covering both of the torque transmitting elements  16 ,  72  in a first switched position, then the torque is transmitted from the intermediate shaft  46  to the drive end bearing  14  via the two torque transmitting elements  16 ,  72 , as shown in  FIG. 2 . If the operator of the hand-held power tool  10  uses an actuating element, not shown in detail, to slide the transmitting sleeve  76  counter to the force flow direction  56 , then the transmitting sleeve  76  is situated in another switched position in which it covers only the torque transmitting element  16  of the drive end bearing  14 , thus interrupting a torque transmission from the intermediate shaft  46  to the drive end bearing  14  or more precisely, a torque transmission between the two torque transmitting elements  16 ,  72 . 
     The foregoing relates to the preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.