Handheld machine tools with tool holders

Abstract

A handheld machine tool includes a tool holder (150) and a housing, in which a drive motor and a transmission (118) are arranged, the transmission (118) being arranged in a transmission housing (119), the tool holder (150) having a receiving sleeve (209), the receiving sleeve (209) being supported in the transmission housing (119) for rotational movement via at least one bearing element (231, 232), and configured to receive an insert tool (140), and the transmission The transmission housing (119) has a receiving portion (296) with a ring collar (298) for receiving at least one bearing element (231, 232). In the handheld machine tool, a fixing element (280) for fixing the at least one bearing element (231, 232) is provided in the receiving portion (296), and the fixing element (280) is fixed to the ring collar (298) and at least partially closes the receiving portion (296) at an end face (293) of the transmission housing (119).

Description

[Technical Field]

[0001] The present invention relates to a handheld machine tool having a tool holder and a housing, in which a drive motor and a transmission are arranged, the transmission being arranged in the transmission housing, the tool holder having a receiving sleeve, the receiving sleeve being supported in the transmission housing for rotational movement via at least one bearing element and configured to receive an insert tool, and the transmission housing having a receiving section with a ring collar for receiving the at least one bearing element.

[0002] Such handheld machine tools are known from the prior art, which have a transmission arranged in a transmission housing, the tool holder of which has a receiving sleeve that is supported in the transmission housing for rotational movement via at least one bearing element, and the transmission housing has a receiving section with a ring collar for receiving the at least one bearing element.

[0003] Disclosure of the Invention The invention relates to a handheld machine tool having a tool holder and a housing, in which a drive motor and a transmission are arranged, the transmission being arranged in the transmission housing, the tool holder having a receiving sleeve, the receiving sleeve being supported in the transmission housing for rotational movement via at least one bearing element and configured to receive an insert tool, the transmission housing having a receiving section with a ring collar for receiving the at least one bearing element, and a fixing element for fixing the at least one bearing element provided in the receiving section, the fixing element being fixed to the ring collar and at least partially closing the receiving section at an end face of the transmission housing.

[0004] With this configuration, the present invention can provide a handheld machine tool with a tool holder, which can enable a stable and robust fixation of at least one bearing element by means of a fixing element.

[0005] Preferably, the fixing element is formed as a pot-shaped part with a sleeve-shaped base body, on which a ring collar for support in the transmission housing and a disk-shaped bottom surface for at least partially closing the receiving portion are formed.

[0006] This arrangement makes it possible in a simple manner to suitably fix the at least one bearing element in the receiving part.

[0007] A transmission cover is preferably arranged on the outer periphery of the transmission housing, which forms a receiving portion facing the ring collar of the fixing element, and in the receiving portion a spring element or a buffer element for applying a preload to the fixing element is arranged on the transmission housing.

[0008] This arrangement makes it possible to provide a secure and reliable arrangement of the fixing element on the transmission housing.

[0009] According to one embodiment, at least one bearing element has an associated bearing width in the longitudinal direction of the receiving sleeve, and the disk-shaped bottom surface of the fixing element has a wall thickness that is less than 1 / 4 of the bearing width, preferably less than 1 / 5 of the bearing width.

[0010] In this way, suitable fixing elements can be easily provided.

[0011] Preferably, the disk-shaped bottom surface has a wall thickness of less than 2.2 mm.

[0012] This arrangement makes it possible to provide a compact and at the same time stable fastening element.

[0013] Preferably, the fastening element, in particular the sleeve-shaped base body, is fastened to the outer periphery of the ring collar of the receiving part by means of a press fit or a bonded fit.

[0014] In this way, a robust and stable arrangement of the fastening element in the transmission housing can be ensured.

[0015] According to one embodiment, the fixing element is formed integrally with a transmission cover arranged on the outer periphery of the transmission housing.

[0016] In this way, a simple and compact fixing element can be provided.

[0017] Preferably, the end face of the transmission cover forms the fastening element and has a disk-shaped fastening section.

[0018] With this configuration, the fixing element can be easily formed.

[0019] Preferably, the disk-shaped bottom surface and the disk-shaped fixing section each have a through-opening, the diameter of which is smaller than the outer diameter of the at least one bearing element.

[0020] In this way, fixing of the at least one bearing element in the axial direction can be easily and simply made possible.

[0021] The fixing element or the transmission cover preferably comprises plastic, sheet metal and / or aluminum.

[0022] In this way, a simple and cost-effective fastening element or transmission cover can be provided.

[0023] The invention will be explained in more detail in the following description with reference to an embodiment shown in the drawing. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram of a handheld machine tool with a transmission arranged in a transmission housing; FIG. [Figure 2] 2 is a longitudinal section through the transmission housing together with the transmission shown in FIG. 1, the support device for the tool holder and the fixing element; FIG. [Figure 3] 3 shows an enlarged portion of a longitudinal section through the support device and the fixing element of the tool holder shown in FIG. 2; [Figure 4] 4 is an exploded view of the transmission housing together with the fixing element and housing cover shown in FIGS. 2 and 3. FIG. [Figure 5] FIG. 5 is a perspective view showing the fixing element shown in FIGS. 2 to 4. [Figure 6] FIG. 5 is a perspective view showing the transmission cover shown in FIGS. 2 to 4. [Figure 7] 2 is a longitudinal section of the transmission housing shown in FIG. 1, a support device for the tool holder, and an alternative fixing element; FIG.

[0025] Description of Examples In the drawings, elements having the same or comparable function are given the same reference numerals and will be described in more detail only once.

[0026] 1 shows a handheld machine tool 100 provided with a tool holder 150, the handheld machine tool 100 having a housing 110 with a grip 126. According to one embodiment, the handheld machine tool 100 is mechanically and electrically connectable to a battery pack 130 for grid-independent power supply.

[0027] Arranged within the housing 110 are an electric drive motor 114 and a transmission 118, which in the illustrated embodiment is supplied with current from a battery pack 130. The drive motor 114 can be operated, i.e., connected and disconnected, for example, via a hand switch 128 and can be any motor type, such as an electronically commutated motor or a DC motor. Preferably, the drive motor 114 can be electronically controlled in an open or closed loop so that reverse operation and setting of the desired rotation speed can be achieved. The function and design of suitable drive motors are sufficiently known from the prior art and will not be described in detail here for the sake of brevity.

[0028] The drive motor 114 is connected via the associated motor shaft 116 to a transmission 118, which converts the rotation of the motor shaft 116 into the rotation of the driven shaft 124. This conversion preferably takes place in such a way that the driven shaft 124 rotates with increased torque relative to the motor shaft 116 but at a reduced rotational speed. In the illustrated embodiment, the drive motor 114 is arranged in a motor housing 115. The transmission 118 is arranged in a transmission housing 119. The transmission housing 119 and the motor housing 115 are arranged, for example, in the housing 110.

[0029] According to one embodiment, a mechanical striking mechanism 122 is provided. The drive motor 114 is connected via a motor shaft 116 to a transmission 118 such that rotation of the motor shaft 116 is converted into rotation of an intermediate shaft 120 provided between the transmission 118 and the striking mechanism 122. The mechanical striking mechanism 122 and / or the transmission 118 are arranged in a common transmission housing 119 in the illustrated embodiment. Alternatively, the mechanical striking mechanism 122 may be arranged in a separate striking mechanism housing.

[0030] The mechanical striking mechanism 122 coupled to the intermediate shaft 120 is, for example, a rotary striking mechanism, which generates a high-intensity rotary striking pulse and transmits it to the driven shaft 124, for example, a driven spindle. Hereinafter, the mechanical striking mechanism will be referred to as the "mechanical rotary striking mechanism 122." In particular, the mechanical rotary striking mechanism 122 is provided to strike and drive the tool holder 150. The mechanical rotary striking mechanism 122 has a spring-loaded striking body (205 in FIG. 2), which is connected to the intermediate shaft 120 and supported by the intermediate shaft 120 so as to be movable in the axial direction 102 of the transmission 118.

[0031] The driven shaft 124 is provided with a tool holder 150, which is preferably configured to receive a tool insert and can be coupled to a tool insert 140, preferably having an external polygonal connection. The tool insert 140 is configured, for example, as a screwdriver bit with an external polygonal connection, an octagonal connection in the illustrated embodiment. Such screwdriver bits are sufficiently known in the prior art and will not be described in detail here for the sake of brevity. Furthermore, in the illustrated embodiment, a locking unit 190 is provided for locking and unlocking the tool insert 140 placed in the tool holder 150.

[0032] 2 shows the transmission 118 arranged in the transmission housing 119 shown in FIG. 1 and an optional mechanical rotary impact mechanism 122 with the intermediate shaft 120 shown in FIG. 1. In the illustrated embodiment, the optional mechanical impact mechanism 122 has a spring-loaded impact body 205 and an anvil 220 that can be loaded by the impact body 205. Preferably, the anvil 220 of the tool holder 150 is associated with, in particular, a receiving sleeve 209 belonging to the tool holder 150. Preferably, the anvil 220 is formed integrally with the receiving sleeve 209. In the illustrated embodiment, the anvil 220 is oriented transversely, in particular substantially perpendicularly, to the receiving sleeve 209.

[0033] The mechanical striking mechanism 122 generates a high-intensity rotary impact pulse and transmits the rotary impact pulse to the driven shaft 124 or to the receiving sleeve 209 of the tool holder 150 via the anvil 220. A spring-loaded striking body 205 is supported on the transmission 118 so as to be movable in the axial direction 102 shown in FIG. 1. Such rotary mechanical striking mechanisms 122 are well known in the prior art and will not be described in detail here for the sake of brevity.

[0034] Preferably, the receiving sleeve 209 is configured to receive the insertion tool 140. The receiving sleeve 209 is supported for rotational and axial movement, preferably in the radial direction, within bearing elements 231, 232 fixed in the transmission housing 119. In the illustrated embodiment, the transmission housing 119 has two sections 292, 294 connected to one another. The section 294 is preferably configured as a cover fixed to the section 292.

[0035] 2 also shows an insertion tool 140, which in the illustrated embodiment is configured as a bit tool and which is locked in the tool holder 150 or in the receiving sleeve 209. The insertion tool 140 can be unlocked by a preferably axial movement of an operating sleeve 250 of a locking unit, which is not further shown.

[0036] In the illustrated embodiment, the tool holder 150 has a longitudinal extension 203. It should be noted that the term "axial direction" in the context of the present invention refers to a direction along the longitudinal extension 203 of the tool holder 150. Furthermore, the term "radial direction" refers to a direction approximately perpendicular to the longitudinal extension 203 of the tool holder 150. The radial direction 202 is therefore approximately perpendicular to the axial direction 102 of the transmission 118 shown in FIG. 1 or to the direction along the longitudinal extension 203 of the tool holder 150. Furthermore, the axial direction 102 is substantially parallel to the longitudinal extension 203 of the tool holder 150 or to the rotation axis 201 of the tool holder 150.

[0037] Preferably, the transmission housing 119, in particular the section 292, has a receiving portion 296 with a ring collar 298 for receiving at least one bearing element 231, 232. Preferably, the transmission housing 119, in particular the section 292, forms the receiving portion 296. In the illustrated embodiment, the at least one bearing element 231, 232 is preferably arranged radially between the transmission housing 119 and the receiving sleeve 209. In the illustrated embodiment, two bearing elements 231, 232 are arranged in the receiving portion 296 of the transmission housing 119. The illustrated two bearing elements 231, 232 are in axial contact along the rotation axis 201 of the tool holder 150, i.e., the two bearing elements 231, 232 are in contact with each other. According to one embodiment, the bearing elements 231, 232 are configured as rolling bearings, in particular as ball bearings.

[0038] Preferably, a damping ring 270 is provided, which is preferably arranged in the transmission housing 119 and is designed to damp the impact energy transmitted by the impact body 205 to the transmission housing 119. The damping ring 270 is oriented towards the impact body 205 and is preferably arranged at least partially axially between the anvil 220 and the bearing elements 231, 232.

[0039] According to the invention, a fixing element 280 for axially fixing at least one bearing element 231, 232 is provided in the receiving portion 296. In this embodiment, the fixing element 280 is fixed to a ring collar 298 and preferably at least partially closes the receiving portion 296 at an end face 293 of the transmission housing 119 facing away from the handheld machine tool 100 shown in FIG. 1 . The end face 293 is preferably arranged facing the operating sleeve 250.

[0040] According to one embodiment, the fixing element 280 is configured as a pot-shaped part with a sleeve-shaped base body 281. The sleeve-shaped base body 281 preferably has a ring collar 282 for support in the transmission housing 119 and a disk-shaped bottom surface 283 for at least partially closing the receiving portion 296.

[0041] Preferably, a transmission cover 240 is arranged on the outer periphery 291 of the transmission housing 119. In this embodiment, an inner side 241 of the transmission cover 240, which faces the transmission housing 119 or the section 292, is arranged on the outer periphery 291 of the transmission housing 119 or the section 292. An end face 249 of the transmission cover 240 and a disk-shaped bottom face 283 are preferably congruent in the axial direction 203 and form a common plane.

[0042] Preferably, the transmission cover 240 forms a receiving portion 242 facing the ring collar 282 of the fixing element 280. A spring or damping element 244 for preloading the fixing element 280 is preferably arranged in the receiving portion 242 in the transmission housing 119. Preferably, the ring collar 282 is arranged axially between the section 292 of the transmission housing 119 and the spring or damping element 244. More preferably, an outer periphery 299 of the sleeve-shaped base body 281 of the fixing element 280 is arranged on the inside 241 of the transmission cover 240. In particular, the sleeve-shaped base body 281 is preferably arranged radially between the transmission cover 240 and the ring collar 298 of the receiving portion 296. Preferably, the fixing element 280, in particular the sleeve-shaped base body 281, is fixed to the outer periphery 297 of the ring collar 298 of the receiving portion 296 by press-fitting or joint-fitting.

[0043] Preferably, the fastening element 280 or the transmission cover 240 comprises plastic, sheet metal and / or aluminum. In one embodiment of the fastening element 280 made of sheet metal, the fastening element 280 simultaneously serves as a cooling element. According to one embodiment, the fastening element 280 may be formed as a deep-drawn part.

[0044] Preferably, the disk-shaped bottom surface 283 is provided with a through opening 288 having a diameter 289. The diameter 289 is preferably smaller than the outer diameter 262 of the at least one bearing element 231, 232. Furthermore, the diameter 289 of the through opening 288 is preferably larger than or equal to the inner diameter 261 of the at least one bearing element 231, 232.

[0045] In the illustrated embodiment, the radial ridge 284 of the transmission housing 119 forms an axial support for the at least one bearing element 231, 232 arranged in the receiving space 296, thereby preventing the at least one bearing element 231, 232 from moving in the axial direction 102 of the transmission 118 towards the drive motor 114 or towards the left in the drawing. To this end, the ridge 284 partially closes the receiving space 296 in its radially outer area. According to one embodiment, the ridge 284, together with the corresponding recess 276 in the damping ring 270, forms an anti-rotation device for the damping ring 270.

[0046] Preferably, the buffer ring 270 has an inner diameter 265. Preferably, the inner diameter 265 is smaller than the outer diameter 262 of the bearing elements 231, 232. Furthermore, the inner diameter 265 of the buffer ring 270 is preferably larger than or equal to the inner diameter 261 of the bearing elements 231, 232. This allows the buffer ring 270 to likewise axially support the bearing element 231 in the region of its inner diameter 265.

[0047] Preferably, in the illustrated embodiment, the two bearing elements 231, 232 are arranged axially between the raised portion 284 and / or the damping ring 270 and the disk-shaped bottom surface 283 of the fixing element 280. This allows the forces acting on the bearing elements 231, 232 to be introduced into the housing 110 of the handheld machine tool 100 shown in Figure 1. Additionally, the handheld machine tool 100 or any rotary impact mechanism 122 may be configured without the damping ring 270.

[0048] Figure 3 shows the arrangement of the fixing element 280 in section 292 of the transmission housing 119 shown in Figure 2. Figure 3 reveals the wall thickness 310 of the disk-shaped bottom surface 283 of the fixing element 280. The wall thickness 310 is preferably less than 2.2 mm, and more preferably less than 1 mm.

[0049] Furthermore, at least one bearing element 231, 232 has, in the longitudinal or axial direction 203 of the receiving sleeve 209, an associated bearing width 320 in the illustrated embodiment. Preferably, the wall thickness 310 is less than one-quarter of the bearing width 320. Particularly preferably, the wall thickness 310 is less than one-fifth of the bearing width 320.

[0050] In the illustrated configuration with two bearing elements 231, 232, each bearing element 231, 232 has a single bearing width 330, 340. The bearing width 320 is then made up of two single bearing widths 330, 340. Additionally, more than two bearing elements 231, 232 may be provided.

[0051] In Figure 4, the transmission housing 119, the receiving portion 296 with a ring collar 298 for receiving the bearing elements 231, 232, the fixing element 280, the spring or buffer element 244 for preloading the fixing element 280 in the transmission housing 119, and the transmission cover 240 shown in Figures 2 and 3 are shown in an exploded view to clarify an example of assembly.

[0052] Figure 5 shows the fixing element 280 shown in Figures 2 to 4. Figure 5 reveals a sleeve-shaped base body 281 with a ring collar 282 for support in the transmission housing 119 shown in Figures 2 to 4, and a disk-shaped bottom surface 283 for at least partially closing the receiving section 296 in the transmission housing 119.

[0053] Figure 6 shows the transmission cover 240 of the transmission housing 119 shown in Figures 2 to 4. Figure 6 reveals a receiving portion 242 formed on the inside 241 of the transmission cover 240 for receiving the spring or damping element 244 shown in Figures 2 to 4.

[0054] Figure 7 shows an alternative arrangement of a fixing element 780 in section 292 of transmission housing 119 shown in Figures 2 to 4. The fixing element 780 is preferably formed integrally with the transmission cover 240, which is arranged on the outer periphery 291 of the transmission housing 119. In the illustrated embodiment, the fixing element 780 is formed on end face 249 of the transmission cover 240. End face 249 has a disk-shaped fixing section 710. Like fixing element 280 shown in Figures 2 to 5, fixing section 710 preferably has a wall thickness 720 of at least 2.4 mm.

[0055] Preferably, the disk-shaped fixing section 710 has a through opening 740. The diameter 730 of the through opening 740 is preferably smaller than the outer diameter 262 of the bearing elements 231, 232. Furthermore, the diameter 730 of the through opening 740 is larger than or equal to the inner diameter 261 of the bearing elements 231, 232.

[0056] According to the embodiment shown in Figure 7, the spring or damping element 244 shown in Figures 2 to 4 is not necessary. The inner side 241 of the transmission cover 240 therefore contacts the outer periphery 291 of the transmission housing 119 or section 292.

Claims

1. A handheld machine tool (100) comprising a tool holder (150) and a housing (110), in which a drive motor (114) and a transmission (118) are arranged, the transmission (118) being arranged in a transmission housing (119), the tool holder (150) having a receiving sleeve (209), the receiving sleeve (209) being supported in the transmission housing (119) for rotational movement via at least one bearing element (231, 232), and configured to receive an insert tool (140), the transmission housing (119) having a receiving portion (296) with a ring collar (298) for receiving the at least one bearing element (231, 232), A fixing element (280) for fixing the at least one bearing element (231, 232) is provided in the receiving portion (296), the fixing element (280; 780) being fixed to the ring collar (298) and at least partially closing the receiving portion (296) at the end face (293) of the transmission housing (119). A handheld machine tool (100) characterized by:

2. 2. The handheld machine tool according to claim 1, wherein the fixing element (280) is formed as a pot-shaped part with a sleeve-shaped base body (281), on which a ring collar (282) for support in the transmission housing (119) and a disk-shaped bottom surface (283) for at least partially closing the receiving space (296) are formed.

3. 3. A handheld machine tool according to claim 2, wherein a transmission cover (240) is arranged on the outer periphery (291) of the transmission housing (119), the transmission cover (240) forming a receiving portion (242) facing the ring collar (282) of the fixing element (280), and a spring or buffer element (244) for preloading the fixing element (280) is arranged in the receiving portion (242) on the transmission housing (119).

4. 4. A handheld machine tool according to claim 2 or 3, wherein the at least one bearing element (231, 232) has an associated bearing width (320) in the longitudinal direction of the receiving sleeve (209), and the disk-shaped bottom surface (283) of the fixing element (280) has a wall thickness (310) that is smaller than 1 / 4 of the bearing width (320), preferably smaller than 1 / 5 of the bearing width (320).

5. 5. A handheld machine tool according to claim 2, wherein the disk-shaped bottom surface (283) of the fixing element (280) has a wall thickness (310) of less than 2.2 mm.

6. 6. A handheld machine tool according to claim 2, wherein the fixing element (280), in particular the sleeve-shaped base body (281), is fixed to the outer periphery (297) of the ring collar (298) of the receiving part (296) by press fitting or joint fitting.

7. 2. The handheld machine tool according to claim 1, wherein the fixing element (780) is formed integrally with a transmission cover (240) arranged on the outer periphery (291) of the transmission housing (119).

8. 8. The handheld machine tool according to claim 7, wherein an end face (249) of the transmission cover (240) forms the fixing element (780), the end face (249) having a disk-shaped fixing section (710).

9. 9. A handheld machine tool according to claim 2, wherein the disk-shaped bottom surface (283) and the disk-shaped fixing section (710) each have one through-opening (288; 740), the diameter (289; 730) of which is smaller than the outer diameter (262) of the at least one bearing element (231, 232).

10. 10. The handheld machine tool according to claim 2, wherein the fixing element (280) or the transmission cover (240) comprises plastic, sheet metal and / or aluminum.

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