Patent Publication Number: US-2023139577-A1

Title: Hand-Held Power Tool with a Motor Support for a Drive Motor

Description:
This application claims priority under 35 U.S.C. § 119 to patent application no. DE 10 2021 212 391.0, filed on Nov. 3, 2021 in Germany, the disclosure of which is incorporated herein by reference in its entirety. 
     The present disclosure relates to a hand-held power tool, in particular a hammer drill, having a tool holder and a housing which has two housing half-shells, wherein a drive unit for driving a tool holder is arranged in the housing, wherein the drive unit comprises at least one drive motor arranged in a motor support and a gear unit arranged in a gear unit housing. 
     BACKGROUND 
     Such a hand-held power tool designed as a hammer drill is known from the prior art. The hand-held power tool comprises a housing which has two housing half-shells and in which a drive unit with a drive motor and a gear unit for driving a tool holder is arranged. The drive motor is arranged in a motor support and the gear unit is arranged in a gear unit housing. The motor support, the gear unit housing and the housing half-shells are connected to one another via a screw connection. 
     SUMMARY 
     The disclosure relates to a hand-held power tool, in particular a hammer drill, having a tool holder and a housing which has two housing half-shells, wherein a drive unit for driving a tool holder is arranged in the housing, and wherein the drive unit has at least one drive motor arranged in a motor support and a gear unit arranged in a gear unit housing. The motor support is connected directly to at least one of the two housing half-shells via at least one non-positive connection and at least one positive-locking connection, wherein a relevant fastening axis is assigned to the at least one non-positive connection and to the at least one positive-locking connection, said fastening axis being arranged at right angles to and at a distance from an axis of rotation assigned to the tool holder. 
     The disclosure thus makes it possible to provide a hand-held power tool in which the at least one non-positive connection and the at least one positive-locking connection between the motor support and at least one housing half-shell can make it possible to improve rigidity and robustness of the hand-held power tool. In addition, a reduction in installation space can be made possible. 
     The motor support preferably has, on its outer surface, at least one positioning opening formed along the fastening axis for the formation of the at least one positive-locking connection to the at least one of the two housing half-shells. The at least one of the two housing half-shells preferably has, on its inner side facing the motor support, at least one positioning boss arranged along the fastening axis and assigned to the positioning opening for the formation of the at least one positive-locking connection to the motor support. 
     The at least one positive-locking connection between the motor support and the at least one housing half-shell can thus be formed in a simple manner both on the motor support side and on the housing half-shell side. 
     The motor support preferably has, on its outer surface, at least one fastening rib arranged along the axis of rotation with a screw eye formed at right angles to the axis of rotation for the formation of the at least one non-positive connection to the at least one of the two housing half-shells. The at least one of the two housing half-shells preferably has, on its inner side facing the motor support, at least one screw boss arranged along the fastening axis and assigned to the screw eye for the formation of the at least one non-positive connection to the motor support. 
     The at least one non-positive connection between the motor support and the at least one housing half-shell can thus be formed in a simple and uncomplicated manner both on the motor support side and on the housing half-shell side. 
     The at least one screw boss preferably has a pressing surface against which the fastening rib is applied. 
     Exact positioning of the motor support can thus be made possible in a simple manner. 
     According to one embodiment, the two housing half-shells each have at least one screw boss with an associated pressing surface, wherein the screw bosses are designed to be complementary to one another, and wherein the motor support, in particular the fastening rib, is arranged between the two pressing surfaces and, by means of a screw, the two housing half-shells and the motor support are connected to one another. 
     A stable and robust connection between the motor support and the housing half-shells can thus be formed. 
     The motor support is preferably formed in one piece. 
     A compact motor support can thus be provided, as a result of which a comparatively precise concentricity of the bearing points can also be made possible. In addition, the drive motor can be arranged in the motor support before being mounted in the hand-held power tool and can be checked before installation in the hand-held power tool. 
     On its outer surface, the motor support preferably has at least two screw bosses oriented along the axis of rotation, the motor support being fastened to the gear unit housing via the screw bosses. 
     A stable and robust connection of the motor support to the gear unit housing can thus be made possible. 
     According to one embodiment, an intermediate flange is arranged between the motor support and the gear unit housing. 
     A secure and reliable arrangement of the motor support on the gear unit housing can thus be made possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure is explained in more detail in the following description on the basis of exemplary embodiments illustrated in the drawings. In the drawings: 
         FIG.  1    is a schematic view of a hand-held power tool with a housing and a drive unit, 
         FIG.  2    is a partial exploded view of the housing and the drive unit of the hand-held power tool of  FIG.  1   , 
         FIG.  3    is a perspective view of the drive unit of  FIG.  1    and  FIG.  2    with the open housing of  FIG.  1    and  FIG.  2   , 
         FIG.  4    is a section through the drive unit arranged in the housing of  FIG.  1    to  FIG.  3   , and 
         FIG.  5    is a perspective view of a detail of a housing half-shell assigned to the housing of  FIG.  1    to  FIG.  4   . 
     
    
    
     DETAILED DESCRIPTION 
     Elements having the same or a comparable function are provided with identical reference numerals in the figures and described in more detail only once. 
       FIG.  1    shows an exemplary hand-held power tool  100  with a housing  105 , in which preferably a drive unit  125  for rotatingly driving a tool holder  140  is arranged. The housing  105  preferably has two housing half-shells  106 . The tool holder  140  is designed illustratively for receiving an insertion tool  198  and during operation rotates about an axis of rotation  199 . 
     In the exemplary embodiment shown, the drive unit  125  illustratively has at least one drive motor  180  and a gear unit  120 . The drive motor  180  is preferably designed as an electronically commutated motor. The drive motor  180  can preferably be switched on and off via a manual switch  195 , wherein the manual switch  195  is illustratively arranged on a handle  115  of the housing  105 . The drive motor  180  is preferably arranged in a motor support  182 . The motor support  182  is preferably formed in one piece. 
     The gear unit  120  is preferably designed as planetary gearing, in particular as switchable planetary gearing. The planetary gearing  120  is preferably arranged in a gear unit housing  122 . An operating element  127  for manual gear-shifting by a user is preferably assigned to the planetary gearing  120 . For the sake of simplicity, the planetary gearing  120 , which is preferably designed as a switchable gear unit, is hereinafter referred to solely as the “gear unit  120 .” 
     Furthermore, the hand-held power tool  100  optionally has a torque adjustment device with a torque adjustment sleeve  197 . Such a torque adjustment device is sufficiently known from the prior art so that a detailed description of the torque adjustment device is dispensed with here for the sake of brevity of the description. 
     Illustratively, for mains-independent power supply the hand-held power tool  100  is mechanically and electrically connectable to a battery pack  190 , and can alternatively or additionally also be operable in a mains-dependent manner. By way of example, the hand-held power tool  100  is designed as a hammer drill or impact drill screwdriver with an impact mechanism  150 . Illustratively, the tool holder  140  is designed as a drill chuck  145 , which is provided by way of example with a protective sleeve  196 . As an alternative to this, the tool holder  140  can however also be designed as a tool attachment, which is detachably arranged on the hand-held power tool  100 . 
     However, the hand-held power tool  100  can also be designed, for example, as a drill driver without an impact mechanism  150 . However, it is pointed out that the present disclosure is not limited to hammer drills, drill drivers or impact drill screwdrivers, but can be used generally in hand-held power tools of which the drive unit  125  has at least one drive motor arranged in a motor support and a housing formed from housing half-shells. 
       FIG.  2    shows the two housing half-shells  106  of the housing  105  and the motor support  182 , as well as the gear unit housing  122  of  FIG.  1   . The motor support  182  illustratively has an approximately cylindrical main body with an outer surface  211 . The drive motor  180  of  FIG.  1    can preferably be arranged in the interior of the motor support  182 . 
     In  FIG.  2   , the motor support  182  is illustratively fastened to the gear unit housing  122  via screw bosses  217 ,  218 ,  219  ( 419  in  FIG.  4   ). On its outer surface  211  the motor support  182  preferably has at least two, illustratively three, preferably four, screw bosses  217 ,  218 ,  219  ( 419  in  FIG.  4   ) oriented along the axis of rotation  199  or along a longitudinal extension of the motor support  182 . A screw connection is formed between the motor support  182  and the gear unit housing  122  via the screw bosses  217 ,  218 ,  219  ( 419  in  FIG.  4   ). For this purpose, a screw (not shown) is assigned to each screw boss  217 ,  218 ,  219  ( 419  in  FIG.  4   ). According to one embodiment, an intermediate flange  290  is arranged between the motor support  182  and the gear unit housing  122 . 
     According to the disclosure, the motor support  182  is connected directly to at least one of the two housing half-shells  106  via at least one non-positive connection ( 411  in  FIG.  4   ) and at least one positive-locking connection ( 412  in  FIG.  4   ). Torque support can thereby be effected via the housing  105  or the housing half-shells  106 . Torque support in the axial direction or along the axis of rotation  199  via the screw bosses  218 ,  219 , ( 419  in  FIG.  4   ) to the intermediate flange is thereby no longer required. 
     A relevant fastening axis  299  is assigned to the at least one non-positive connection ( 411  in  FIG.  4   ) and to the at least one positive-locking connection ( 412  in  FIG.  4   ). All corresponding fastening axes  299  are here preferably arranged at right angles to the axis of rotation  199  and at a distance from the axis of rotation  199 . 
     For this purpose, the motor support  182  preferably has, on its outer surface  211 , at least one positioning opening  212 ,  213  formed along the fastening axis  299 . Illustratively, only two of the preferably four positioning openings  212 ,  213  of the motor support  182  are shown in  FIG.  2   . The positioning openings  212 ,  213  are designed to form at least one positive-locking connection ( 412  in  FIG.  4   ) between the motor support  182  and at least one of the two housing half-shells  106 . 
     Furthermore, the motor support  182  preferably has, on its outer surface  211 , at least one fastening rib  215  arranged along the axis of rotation  199 . Illustratively, two oppositely arranged fastening ribs  215  are shown. Each of the illustratively two fastening ribs  215  has a screw eye  216  formed at right angles to the axis of rotation  199  for the formation of the at least one non-positive connection ( 411  in  FIG.  4   ) to the at least one of the two housing half-shells  106 . 
     Similarly thereto, the at least one of the two housing half-shells  106  has, on its inner side  231  facing the motor support  182 , at least one, illustratively two, positioning bosses  232 ,  233  arranged along the fastening axis  299  and assigned to the positioning opening  212 ,  213  of the motor support  182  for the formation of the at least one positive-locking connection ( 412 ) to the motor support  182 . Furthermore, at least one of the two housing half-shells  106  has, on its inner side  231  facing the motor support  182 , at least one screw boss  235 ,  236  arranged along the fastening axis  299  and assigned to the screw eye  216  for the formation of the at least one non-positive connection ( 411  in  FIG.  4   ) to the motor support  182 . Two screw bosses are shown illustratively, with one screw boss  235  being illustratively arranged at the top and one screw boss  236  being illustratively arranged at the bottom, on the inner side  231 . In this case, a screw boss  235 ,  236  is assigned to each screw eye  216 . 
     According to one embodiment, the at least one screw boss  235 ,  236  has a pressing surface  237  against which the fastening rib  215  of the motor support  182  is applied in the assembled state. The two housing half-shells  106  and the motor support  182  are preferably connected to one another by means of a screw  295  assigned to a screw boss  236 . A screw  295  is assigned to each screw boss  235 ,  236 . 
       FIG.  3    shows the motor support  182  fastened to the gear unit housing  122 , which motor support has been inserted into one of the two housing half-shells  106  of the housing of  FIG.  1    and  FIG.  2   . In this case,  FIG.  3    clearly shows the arrangement of the screw bosses  235 ,  236  in the screw eyes  216  of the fastening ribs  215  of the motor support  182 . Furthermore,  FIG.  3    illustrates the arrangement of the fastening axes  299 , which are preferably arranged perpendicularly or at right angles to the axis of rotation  199 . It can also be seen here that the two fastening axes  299  are arranged parallel to one another and spaced apart from the axis of rotation  199 . 
       FIG.  4    shows the motor support  182  of  FIG.  1    to  FIG.  3    arranged in the housing  105  or in the housing half-shells  106 .  FIG.  4    here illustrates the arrangement of the positioning bosses  232 ,  233  of the respective housing half-shells  106  in the positioning openings  212 ,  213  of the motor support  182  for the formation of the at least one, illustratively four, positive-locking connections  412 . Furthermore,  FIG.  4    illustrates the fastening axes  299  which are arranged at right angles to the axis of rotation  199  and illustratively horizontally. The positive-locking connection  412  has a comparatively small clearance along the axis of rotation  199  and along the fastening axes  299 , whereby undesired wear on the positioning bosses  232 ,  233  and/or the positioning openings  212 ,  213  can be prevented. 
       FIG.  4    also illustrates the two housing half-shells  106 , wherein the illustratively right-hand housing half-shell  106  has a screw boss  435 . Preferably, the two housing half-shells  106  each have at least one screw boss  235 ,  435  with an associated pressing surface  237 ,  437 , wherein the screw bosses  235 ,  435  are designed to be complementary to one another. Furthermore, the motor support  182 , in particular the fastening rib  215 , is, in the assembled state, arranged between the two pressing surfaces  237 ,  437 . 
     Furthermore,  FIG.  4    illustrates the at least one non-positive connection  411 , which is formed between the screw bosses  235 ,  435  of the housing half-shells  106  and the fastening rib  215 .  FIG.  4    shows only a non-positive connection  411 , wherein the two housing half-shells  106  and the motor support  182  are connected to one another by means of the screw  295  assigned to the screw bosses  235 ,  435 . 
     Furthermore,  FIG.  4    shows the preferably four screw bosses  217 ,  218 ,  219 ,  419  of the motor support  182  for fastening the motor support  182  to the gear unit housing  122 . 
       FIG.  5    shows one of the two housing half-shells  106  of the housing  105  of  FIG.  1    to  FIG.  4   .  FIG.  5    here illustrates the arrangement of the at least one, or of the illustratively two, positioning bosses  232 ,  233  on the inner side  231  of the housing half-shell  105 . Furthermore, the arrangement of the at least one, or preferably of the two screw bosses  235 ,  236  with their relevant pressing surface  237  is shown. Illustratively, the two positioning bosses  232 ,  233  are arranged between the preferably two screw bosses  235 ,  236 . The fastening axes  299  of the screw bosses  235 ,  236  and of the positioning bosses  232 ,  233  are arranged parallel to one another, with only one fastening axis  299  being marked with a reference numeral in  FIG.  5   .