Power tool

Abstract

Power tool comprising a drive unit (12), a receiving unit (14), and a fastening unit (66) which is provided for fastening the drive unit (12) when mounted with the receiving unit (14), wherein the receiving unit (14) has a sleeve-shaped receiving element (22) for receiving the drive unit (12), characterized in that the fastening unit (66) has a centering unit (18) which is provided for centering the drive unit (12) when mounted with the receiving unit (14), wherein the centering unit (18) has at least one positive locking element (20) arranged on the receiving unit (14) which is provided for centering the drive unit (12) and which is arranged on a radially inwardly directed surface (24) of the sleeve-shaped receiving element (22).

Description

State of the art

[0001] The invention relates to a power tool according to the preamble of claim 1.

[0002] From DE 10 2005 036 730 A1, an electric tool comprising a drive unit, a mounting unit, and a fastening unit is already known. The mounting unit is designed to receive the drive unit. The fastening unit is designed to secure the drive unit when mounted with the mounting unit, the mounting unit having a sleeve-shaped receiving element for receiving the drive unit.

[0003] Corresponding fastening units for mounting a drive unit in a receiving unit of an electric tool are also shown in DE 196 08 360 A1 and EP 1 323 501 A2.

[0004] The object of the invention is to provide a power tool that enables simplified and safe mounting of a drive unit in a receiving unit of the power tool. Advantages of the invention

[0005] To solve the problem, it is proposed that the mounting unit include a centering unit designed to center the drive unit during assembly with the receiving unit. The centering unit comprises at least one positive locking element arranged on the receiving unit, which is designed to center the drive unit and is located on a radially inwardly directed surface of the sleeve-shaped receiving element. The sleeve-shaped receiving element advantageously provides additional protection for at least a portion of the drive unit by offering an additional stable receiving area for the drive unit. Furthermore, it ensures a preferably stable mounting of the drive unit within the receiving unit. The sleeve-shaped receiving element can be formed by a single component or by multiple parts.The term "receiving unit" is understood to mean, in particular, a unit designed to receive and / or support drive elements and / or transmission elements, such as a motor unit, a drive shaft, a hammer tube, and / or other drive elements that would be considered useful by a person skilled in the art, and / or which is preferably formed by a receiving flange, in particular an intermediate flange, and / or a partial area or section of the electrical device's housing. The term "drive unit" is understood to mean, in particular, a unit comprising a motor with a motor and a motor housing. Furthermore, the drive unit may include a motor sleeve that, in addition to the motor housing, provides protective enclosure for the motor. The term "provided for" is understood to mean, in particular, specially equipped and / or designed.The design according to the invention allows for an advantageous arrangement of the drive unit within the electrical device or the receiving unit. The electrical device is preferably a power tool, in particular a hand-held machine tool.

[0006] The term "centering" is understood to mean, in particular, a process, preferably an insertion process, in which movement in one direction causes at least one corrective movement, generated by the centering unit, in at least one other direction, so that the overall movement results in a desired position. The design according to the invention advantageously enables a particularly precise and backlash-free insertion and / or centering of the drive unit during assembly of the drive unit with the receiving unit, and in particular, backlash-free transmission of a drive torque from the drive unit to another drive element, such as an intermediate shaft, is achieved.

[0007] The positive locking element enables a structurally simple centering or insertion of the drive unit into the receiving unit. In this context, a "positive locking element" is understood to be, in particular, an element that has a shape for centering the drive unit during assembly with the receiving unit.

[0008] It is further proposed that the sleeve-shaped receiving element forms a receiving area which is tapered along a mounting direction by means of the positive locking element, thereby achieving an advantageous orientation of the drive unit. This can be achieved particularly advantageously if the positive locking element has at least one inclined surface along the mounting direction. In this context, a "mounting direction" is understood to mean, in particular, a direction in which the drive unit moves relative to the receiving unit during assembly. An "inclined surface" is understood to mean a surface which, particularly with respect to the mounting direction and / or, in a mounted state, with respect to a motor shaft of the drive unit, has an angle of inclination of preferably greater than 0° and less than 30°, advantageously greater than 0° and less than 20°, and particularly preferably greater than 0° and less than 10°.In principle, instead of an inclined surface, a stepped design and / or other designs of the tapered exception area that appear sensible to the person skilled in the art are also possible in an alternative embodiment of the invention.

[0009] Furthermore, it is proposed that the centering unit has at least one positive locking element that tapers along a mounting direction and is arranged on the drive unit, thereby achieving a particularly large bearing or centering surface between the drive unit and the receiving unit. This preferably results in a centric force application and advantageously avoids undesirable force flows that could impair the power output of the drive unit.

[0010] In an advantageous embodiment of the invention, it is proposed that the receiving unit has at least one fastening element of the fastening unit for fastening the drive unit, whereby, in addition to centering the drive unit, an advantageous fastening of the drive unit in an advantageously centered position can be achieved.

[0011] Furthermore, it is proposed that the fastening element be formed by a locking element and / or bayonet locking element, thereby enabling preferably tool-free attachment of the drive unit to the receiving unit with particularly low assembly effort. In this context, a "bayonet locking element" is understood to mean, in particular, a fastening element that, by means of a combination of a linear insertion movement and a subsequent rotational movement relative to another fastening element, results in a connection or fastening with the other fastening element. Preferably, the drive unit has at least one locking element and / or bayonet locking element corresponding to the fastening element of the receiving unit, so that simple assembly and, in particular, simple disassembly of the drive unit from the receiving unit can be achieved.However, in principle, other fastening elements that would appear useful to a person skilled in the art are also conceivable in an alternative embodiment of the invention.

[0012] Further savings in components, installation space, assembly effort, and costs for mounting the drive unit can be achieved particularly advantageously if the fastening element and the positive locking element are at least partially formed as a single piece. "Single piece" here means, in particular, that the fastening element and the positive locking element form a single component and / or are manufactured from a single casting.

[0013] Furthermore, it is proposed that the drive unit comprises a motor sleeve and a motor unit mounted within the motor sleeve, including a motor housing. This allows for an advantageous modular arrangement, particularly of the motor unit, within the receiving unit, providing especially effective protection of the motor unit against unwanted dust and / or moisture. The term "motor sleeve" here refers specifically to a sleeve designed for attaching and / or coupling the motor unit to the receiving unit, and which, in addition to a motor housing, provides protective enclosure for the motor. drawing

[0014] Further advantages become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0015] They show: Fig. 1. An electrical device formed by a hammer drill, in a side view. Fig. 2. A perspective view of a section of the electrical device with a recording unit and a drive unit, Fig. 3 a section view of a part of the recording unit with the drive unit, Fig. 4 another partial section of the recording unit with the drive unit, Fig. 5 a centering unit with a positive locking element of the receiving unit and a positive locking element of the drive unit and Fig. 6. A section of the electrical device with an alternative recording unit and a drive unit in a perspective view. Description of the exemplary implementations

[0016] In Fig. Figure 1 shows a hand-held power tool 10. The power tool, formed by a rotary hammer, comprises a housing 40 and, in a front area 42, a tool holder 44 for receiving a tool (not shown in detail). The power tool has a drive unit 12 for generating a drive torque. The power tool also includes a mounting unit 14 for supporting and securing the drive unit 12 within the power tool. The drive torque of the drive unit 12 is transmitted to the tool via a gear unit 46 of the power tool.

[0017] The Fig. Figures 2 to 4 show the receiving unit 14 of the hand-held power tool with the drive unit 12 mounted on the receiving unit 14. The receiving unit 14 is designed to receive gear elements and / or drive elements 16 and is formed by an intermediate flange of the hand-held power tool. On a side 48 facing away from the drive unit 12, the receiving unit 14 has a sleeve-shaped receiving element 50, which is designed to receive a drive element formed by a hammer tube and / or a drive element formed by an impact mechanism of the hand-held power tool ( Fig. 2) Furthermore, on the side 48 facing away from the drive unit 12, another drive element 16 is arranged on the intermediate flange. The further drive element 16 is formed by an intermediate shaft, which transmits a drive torque generated by the drive unit 12 to further gear elements, not shown in detail here, during operation of the hand-held power tool.

[0018] The drive unit 12 comprises a motor sleeve 34 and a motor unit 36 ​​mounted within the motor sleeve 34, comprising an electrically operated motor 52, a motor housing 38 and a fan 54, and is coupled to the receiving unit 14 by means of the motor sleeve 34 ( Fig. 2 to 4). The motor sleeve 34 is cylindrical and forms a receiving area 56 for the motor unit 36. Within the receiving area 56 of the motor sleeve 34, the fan 54 is arranged on one side 58 of the motor unit 36 ​​or the motor housing 38, facing away from the receiving unit 14. During operation of the motor unit 36, the fan 54 is driven by a motor shaft 60 of the electrically driven motor 52 and is designed to cool and protect the motor 52 from unwanted overheating. For cooling the motor 52, the motor sleeve 34 also has air outlet openings 62 within a cylindrical wall 64, through which air can flow to cool the motor 52. During operation of the motor unit 36, the air is drawn in by the fan 54 and flows between the motor sleeve 34 and the motor unit 36 ​​from the fan 54 towards the air outlet openings 62 through cooling channels not shown in detail.

[0019] For mounting the drive unit 12 with the receiving unit 14, the hand-held power tool has a fastening unit 66 with a centering unit 18 ( Fig. 4 and Fig. 5) The centering unit 18 is designed to center the drive unit 12 during assembly with the receiving unit 14. For this purpose, the centering unit 18 has a conically shaped positive locking element 20, which is arranged on a radially inwardly directed surface 24 of a sleeve-shaped receiving element 22 of the receiving unit 14, wherein the sleeve-shaped receiving element 22 extends along an axial direction 68 on the side 70 of the receiving unit 14 facing the motor unit 36. By means of the positive locking element 20, the sleeve-shaped receiving element 22 forms a tapered receiving area 72 for receiving the drive unit 12 or the motor sleeve 34 ( Fig. 4 and Fig. 5) The positive locking element 20 has an inclined surface 28 on the radially inwardly directed surface 24 of the sleeve-shaped receiving element 22 along a mounting direction 26 that extends parallel to the axial direction 68. Furthermore, the centering unit 18 has another positive locking element 30 on the drive unit 12 or on the motor sleeve 34. The positive locking element 30 is tapered in the mounting direction 26 and is arranged on a partial area of ​​the receiving unit 14 facing the receiving unit 14. In addition, the positive locking element 30, formed by an inclined surface 74, is arranged on a radially outwardly directed surface 76 of the motor sleeve 34. The tapered receiving area 72 orThe inclined surface 28 together with the molded element 30 enables easy centering within the receiving unit 14 when mounting the drive unit 12 and also a large bearing area between the motor sleeve 34 and the receiving unit 14 or the sleeve-shaped receiving element 22.

[0020] The fastening unit 66 comprises several fastening elements 32 formed by detent elements, which in turn are formed by detent recesses. The detent recesses are arranged on the sleeve-shaped receiving element 22 of the receiving unit 14. The detent recesses of the fastening unit 66 and the positive locking element 20 of the centering unit 18 are also integrally formed on the sleeve-shaped receiving element 22. The drive unit 12, or the motor sleeve 34, has hook-shaped detent elements 78 corresponding to the fastening elements 32 for fastening to the receiving unit 14. These hook-shaped detent elements are arranged on the radially outwardly facing surface 76 of the motor sleeve 34.The hook-like locking elements 78 are arranged on the portion of the motor sleeve 34 facing the receiving unit 14 and engage in the designated locking recesses of the receiving unit 14 for fastening purposes, so that the locking elements form a positive and non-positive connection with the surrounding area of ​​the locking recess. To secure the drive unit in a circumferential direction 80, the locking recesses of the receiving unit 14 are slightly wider than the locking elements 78 of the drive unit 12, but by a maximum of 20% wider than the locking elements of the receiving unit 14. However, it is also conceivable to arrange the fastening element 32 of the drive unit 12 on a surface of the drive unit 12 facing in the mounting direction 26 and / or on other surfaces of the drive unit 12 that would appear suitable to a person skilled in the art.

[0021] For fastening or mounting the drive unit 12 to the receiving unit 14, an O-ring 84 is located circumferentially 80 around the motor unit 36 ​​in a region 82 facing the receiving unit 14. This O-ring ensures a precise and backlash-free fastening of the drive unit 12 to the receiving unit 14 and, together with the motor sleeve 34, creates a preload between the receiving unit 14 and the motor unit 36 ​​in a mounted state. In a further embodiment of the invention, instead of the O-ring 84 for a precise and backlash-free fastening of the motor sleeve 34 or the motor unit 36 ​​to the receiving unit 14, an elastic form element and / or other elements or components that would appear useful to a person skilled in the art are conceivable.In its assembled state, the drive unit 12 is mounted on the receiving unit 14 exclusively via the centering unit 18 and the fastening unit 66, and a region 86 of the drive unit 12 facing away from the receiving unit 14 is arranged to float freely within the hand-held power tool.

[0022] To secure the motor unit 36 ​​to the motor sleeve 34, the motor sleeve 34 has fastening elements 88 which are arranged on a partial area facing the receiving unit 14 and are provided for securing the motor unit 36 ​​in the axial direction 68 ( Fig. 2 to 4). The fastening elements 88 are each formed by a hook-shaped locking element. Furthermore, the locking elements are arranged in the circumferential direction 80 on a radially inwardly directed surface 90 of the motor sleeve 34. The locking elements each have a locking chamfer 94, which is oriented obliquely relative to the cylindrical wall 64 of the motor sleeve 34 and has a radially inwardly directed extension component and an extension component directed in the assembly direction 26. For fastening the motor unit 36, the motor housing 38 has locking elements 92 corresponding to the locking elements of the motor sleeve 34, each formed by a locking recess. The locking recesses have an inclined surface 96 corresponding to the locking elements of the motor sleeve 34, so that a maximum contact area is achieved between the locking elements of the motor sleeve 34 and the locking elements 92 of the motor housing 38.Furthermore, the locking chamfers 94 of the fastening elements 88 and the inclined surfaces 96 of the locking elements 92 ensure a stable position of the motor unit 36 ​​in a mounted state within the motor sleeve 34 in a radial direction 100. The locking recesses have a width in the circumferential direction 80 that is slightly wider than the width of the hook-shaped locking elements of the motor sleeve 34, but at most 20% wider than the width of the hook-shaped locking elements, so that in addition to securing in the axial direction 68, the motor unit 36 ​​is also secured in the circumferential direction 80. However, it is also conceivable that the locking elements 92 of the motor housing 38 or the locking recesses are formed by a circumferential groove. In a further embodiment of the invention, fastening the motor unit 36 ​​to the motor sleeve 34 by means of bayonet locking elements and / or other fastening elements is also conceivable.

[0023] In Fig. Figure 6 shows a further embodiment of the invention. Essentially identical components, features, and functions are generally numbered with the same reference numerals. The following description is essentially limited to the differences from the embodiment in the Fig. 1 to 5, whereby with regard to unchanged components, features and functions, reference is made to the description of the exemplary embodiment in the Fig. 1 to 5 can be referenced.

[0024] A drive unit 12 of the hand-held power tool is arranged with a mounting unit 14 by means of a fastening unit 66. The fastening unit 66 has fastening elements 32 formed by bayonet locking elements. The drive unit 12 comprises a motor unit 36 ​​with an electrically operated motor 52, a motor housing 38, and a fan 54. The drive unit 12 is coupled or fastened to the mounting unit 14 via the motor housing 38 of the drive unit 12. For this purpose, the motor housing 38 has bayonet locking elements 98 that engage in the corresponding fastening elements 32 of the mounting unit formed by the bayonet locking elements.

Claims

[1] Power tool comprising a drive unit (12), a receiving unit (14), and a fastening unit (66) for fastening the drive unit (12) when mounted with the receiving unit (14), wherein the receiving unit (14) has a sleeve-shaped receiving element (22) for receiving the drive unit (12), characterized by , that the fastening unit (66) has a centering unit (18) which is provided for centering the drive unit (12) when mounted with the receiving unit (14), wherein the centering unit (18) has at least one positive locking element (20) arranged on the receiving unit (14) which is provided for centering the drive unit (12) and which is arranged on a radially inwardly directed surface (24) of the sleeve-shaped receiving element (22). [2] Power tool according to claim 1, characterized by, that the sleeve-shaped receiving element (22) forms a receiving area (72) which is tapered along a mounting direction (26) by means of the form-fitting element (20). [3] Power tool according to any one of the preceding claims, characterized by that the positive locking element (20) has at least one inclined surface (28) along the assembly direction (26). [4] Power tool according to claim 1, characterized by , that the centering unit (18) has at least one form-locking element (30) tapering along a mounting direction (26) and arranged on the drive unit (12). [5] Power tool according to any one of the preceding claims, characterized by that the receiving unit (14) has at least one fastening element (32) of the fastening unit (66) for fastening the drive unit (12). [6] Power tool according to claim 5, characterized by , that the fastening element (32) is formed by a snap-fit ​​element. [7] Power tool according to claim 5, characterized by , that the fastening element (32) is formed by a bayonet locking element. [8] Power tool according to claim 5, characterized by that the fastening element (32) and the positive locking element (20) are at least partially formed in one piece. [9] Power tool according to any one of the preceding claims, characterized by , that the drive unit (12) has a motor sleeve (34) and a motor unit (36) mounted in the motor sleeve (34) with a motor housing (38).

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