Hand-held power tool having mechanical rotary impact mechanism

Abstract

The invention relates to a hand-held power tool (100) having a tool receptacle (150) and a housing (110) in which a drive motor (114) and a transmission device (118) are arranged, the transmission device (118) being associated with a mechanical rotary percussion mechanism (122) for percussively driving the tool receptacle (150), the tool receptacle (150) being associated with a receiving sleeve (299), the receiving sleeve (299) being in contact with the drive motor (114) and the transmission device (118). The transmission (118) and the mechanical rotary percussion mechanism (122) are arranged in a transmission housing (119), the mechanical rotary percussion mechanism (122) having a percussion body (210) and an anvil (220) associated with the receiving sleeve (299), and wherein the mechanical rotary percussion mechanism (122) is arranged in the transmission housing (119). The receiving sleeve (299) is mounted in a rotatably and axially displaceable manner radially in a bearing element (231, 232) fixed in the transmission housing (119), a damping ring (270) is provided, which damping ring is arranged axially in the transmission housing (119) facing the impact body (210) and at least in some regions between the anvil (220) and the bearing element (231, 232), wherein the buffer ring (270) has an inner diameter (263), which is smaller than an outer diameter (262) of the bearing elements (231, 232).

Description

Technical Field

[0001] The present invention relates to a hand-held machine tool, which has a tool receiving part and a housing, in which a drive motor and a transmission device are arranged, wherein the transmission device is equipped with a mechanical rotary impact mechanism for driving the tool receiving part in an impact manner, wherein the tool receiving part is equipped with a receiving sleeve, wherein the transmission device and the mechanical rotary impact mechanism are arranged in the transmission housing, wherein the mechanical rotary impact mechanism has an impact body and an anvil associated with the receiving sleeve, and wherein the receiving sleeve is radially supported in a bearing element fixed in the transmission housing in a rotatable and axially displaceable manner. Background Art

[0002] Such handheld power tools in the form of rotary impact screwdrivers are known from the prior art and have a mechanical rotary impact mechanism. The mechanical rotary impact mechanism has a spring-loaded impact body and an anvil. During the impact drive of the mechanical rotary impact mechanism, in which the impact body strikes the anvil axially, in addition to the desired drive impact, undesirable vibrations and force impacts are generated which act on the transmission housing. Summary of the invention

[0003] The invention relates to a hand-held power tool, which has a tool receiving part and a housing, in which a drive motor and a transmission are arranged, wherein the transmission is equipped with a mechanical rotary impact mechanism for driving the tool receiving part in an impacting manner, wherein the tool receiving part is equipped with a receiving sleeve, wherein the transmission and the mechanical rotary impact mechanism are arranged in the transmission housing, wherein the mechanical rotary impact mechanism has an impact body and an anvil associated with the receiving sleeve, and wherein the receiving sleeve is supported in a radial direction in a bearing element fixed in the transmission housing in a rotatable and axially displaceable manner. A damping ring is provided, which is arranged axially in the transmission housing facing the impact body and at least in a region between the anvil and the bearing element, wherein the inner diameter of the damping ring is smaller than the outer diameter of the bearing element.

[0004] Therefore, the present invention can provide a handheld power tool having a mechanical rotary impact mechanism, in which the unwanted vibration and impact force when the mechanical rotary impact mechanism impacts, that is, the impact body axially strikes the anvil, are damped by the buffer ring, so that damage or destruction of the transmission housing caused by the unwanted vibration and force impact can be effectively prevented.

[0005] The outer diameter of the damping ring is preferably greater than the outer diameter of the bearing element.

[0006] Arranging the damping ring radially outside the bearing element can thus be achieved easily and uncomplicatedly.

[0007] The inner diameter of the damping ring is preferably larger than the inner diameter of the bearing element.

[0008] Axial support of the bearing element by the damping ring can thus be achieved in a simple manner.

[0009] According to one embodiment, the damping ring has an anti-rotation element on its outer circumference for forming an anti-rotation structure.

[0010] Therefore, a safe and reliable anti-twist structure of the buffer ring can be provided.

[0011] The anti-rotation element preferably has at least one anti-rotation rib which is preferably oriented radially.

[0012] Therefore, a rotation-proof structure can be formed in a simple manner.

[0013] The transmission housing preferably has a receiving element which corresponds to the rotation-proof element.

[0014] Therefore, a positive locking structure can be easily and uncomplicatedly formed as a rotation prevention structure.

[0015] According to one embodiment, the damping ring has at least one groove between its outer diameter and its inner diameter.

[0016] Thus, an alternative rotation prevention structure can be provided in a simple manner.

[0017] The gear housing preferably has at least one projection on its inner side facing the tool receptacle for being arranged in at least one groove of the damping ring.

[0018] Thus, an alternative anti-twist structure can be easily and uncomplicatedly formed.

[0019] According to one embodiment, at least two bearing elements are provided, which are in axial contact along the axis of rotation of the tool receiving part.

[0020] Thus, a compact arrangement of at least two bearing elements can be achieved.

[0021] The damping ring preferably comprises sheet steel and / or plastic.

[0022] Thus, an uncomplicated and low-cost buffer ring can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The invention is explained in more detail in the following description based on the exemplary embodiments shown in the accompanying drawings. The accompanying drawings show:

[0024] Figure 1 : Schematic diagram of a handheld machine tool having a mechanical rotary impact mechanism;

[0025] Figure 2: With a buffer ring arranged in the transmission housing Figure 1 A longitudinal section of a mechanical rotary impact mechanism;

[0026] Figure 3 : Figure 2 A three-dimensional top view of a buffer ring arranged in a transmission housing;

[0027] Figure 4 : Figure 2 and Figure 3 A three-dimensional view of a buffer ring;

[0028] Figure 5 : Figures 1 to 3 A front view of a transmission housing;

[0029] Figure 6 : Figures 1 to 3 Longitudinal section of the transmission housing.

[0030] In the figures, elements having the same or similar functions are provided with the same reference symbols and are described in detail only once. DETAILED DESCRIPTION

[0031] Figure 1 A handheld power tool 100 is shown which is provided with a tool receptacle 150 and has a housing 110 with a handle 126. According to one specific embodiment, the handheld power tool 100 can be mechanically and electrically connected to a battery pack 130 for a mains-independent power supply.

[0032] An electric drive motor 114 powered by a battery pack 130, a transmission 118 and a mechanical impact mechanism 122 are arranged in the housing 110 as shown. The drive motor 114 can be operated, i.e. switched on and off, for example, by a manual switch 128 and can be any type of motor, such as an electronically commutated motor or a DC motor. The drive motor 114 is preferably electronically controllable or adjustable, so that not only reverse operation but also a presetting can be achieved with respect to a desired rotational speed. The working mode and structure of suitable drive motors are sufficiently known from the prior art, so that a detailed description thereof is omitted here for the sake of a brief description.

[0033] The drive motor 114 is connected to a transmission 118 via an associated motor shaft 116, which converts the rotation of the motor shaft 116 into the rotation of an intermediate shaft 120 disposed between the transmission 118 and the impact mechanism 122. The conversion is preferably performed as follows, so that the intermediate shaft 120 rotates with an increased torque but a reduced speed relative to the motor shaft 116. The drive motor 114 is arranged in a motor housing 115 as shown. The mechanical rotary impact mechanism 122 and / or the transmission 118 are arranged, for example, in a transmission housing 119. The transmission housing 119 and the motor housing 115 are arranged in the housing 110 as shown. Alternatively, the mechanical rotary impact mechanism 122 can also be arranged in a separate impact mechanism housing.

[0034] The mechanical impact mechanism 122 connected to the intermediate shaft 120 is, for example, a rotary or rotating impact mechanism, which generates a high-intensity impact-shaped rotation pulse and transmits it to the output shaft 124, for example, the output spindle. The mechanical impact mechanism is referred to as "mechanical rotary impact mechanism 122" below. In particular, the mechanical rotary impact mechanism 122 is configured to drive the tool receiving part 150 in an impact manner and is assigned to the tool receiving part. The mechanical rotary impact mechanism 122 is illustrated as having a spring-loaded impact body ( Figure 2 210 in the figure), which is coupled to the intermediate shaft 120 and is supported on the intermediate shaft 120 so as to be movably supported in the axial direction 102 of the transmission 118.

[0035] A tool receptacle 150 is provided on the output shaft 124, which is preferably designed to receive an inserted tool and can be connected to an inserted tool 140 with an outer polygonal coupler according to one embodiment. The inserted tool 140 is designed, for example, as a screwdriver bit with an outer polygonal coupler, illustrated as an octagonal coupler. Such screwdriver bits are sufficiently known from the prior art that a detailed description thereof is omitted here for the sake of brevity.

[0036] Figure 2 Shown arranged in Figure 1 The transmission 118 in the transmission housing 119 and Figure 1 The mechanical rotating impact mechanism 122 and the intermediate shaft 120. Here, Figure 2 The mechanical rotary impact mechanism 122 is shown schematically, which preferably has a spring-loaded impact body 210 and an anvil 220 that can be loaded by the impact body 210. The anvil 220 is preferably assigned to the tool receptacle 150, in particular to a receiving sleeve 299 of the tool receptacle 150. The anvil 220 is preferably constructed integrally with the receiving sleeve 299. Here, the anvil 220 is illustrated transversely to the receiving sleeve 299, in particular substantially perpendicularly.

[0037] The mechanical rotary impact mechanism 122 generates a high-intensity impact-shaped rotary pulse and transmits it to the output shaft 124 or to the receiving sleeve 299 of the tool receiving part 150 via the anvil 220. The spring-loaded impact body 210 is supported so that it can move in the axial direction 102 of the transmission 118. Such a mechanical rotary impact mechanism 122 is sufficiently known from the prior art, so that a detailed description thereof is omitted here for the sake of brevity.

[0038] Preferably, Figure 1 The insert tool 140 can be arranged in the receiving sleeve 299. The receiving sleeve 299 is preferably supported radially in a rotationally movable and axially displaceable manner in bearing elements 231, 232 fixed in the transmission housing 119. As shown in the figure, the transmission housing 118 has two sections 291, 292 connected to each other. The section 291 is preferably designed as a cover fastened to the section 292.

[0039] According to the invention, a damping ring 270 is provided, which is preferably arranged in the gear housing 119 and is designed to damp the impact energy transmitted to the gear housing 119 by the impact body 210. Here, the damping ring 270 faces the impact body 210 and is preferably arranged axially at least in a region between the anvil 220 and the bearing elements 231, 232. At least one bearing element 231, 232 is arranged in a receiving portion 296 of the gear housing 119 or a section 292 of the gear housing 119. Here, at least one bearing element 231, 232 is arranged radially between the gear housing 118 and the receiving sleeve 299. In the figure, two bearing elements 231, 232 are arranged in the receiving portion 296 of the gear housing 119. The two bearing elements 231, 232 shown in the figure are in axial contact along the rotation axis 201 of the tool receiving portion 150, that is, they are in contact with each other. According to one embodiment, the bearing elements 231, 232 are designed as rolling bearings, in particular ball bearings.

[0040] As shown, the tool receiving part 150 has a longitudinal extension 203. It should be pointed out that in the context of the present invention, the term "axial" is understood as a direction along the longitudinal extension 203 of the tool receiving part 150. In addition, the term "radial" is understood as a direction approximately perpendicular to the longitudinal extension 203 of the tool receiving part 150. Therefore, the radial direction 202 is approximately perpendicular to the axial direction 102 of the transmission 118 or is arranged along the longitudinal extension 203 of the tool receiving part 150. In addition, the axial direction 102 is arranged substantially parallel to the longitudinal extension 203 of the tool receiving part 150 or parallel to the rotation axis 201 of the tool receiving part 150.

[0041] The damping ring 270 preferably has an inner diameter 263 facing the receiving sleeve 299 and an outer diameter 264 facing away from the receiving sleeve 299. The inner diameter 263 is preferably smaller than the outer diameter 262 of the bearing elements 231, 232. In addition, the outer diameter 264 of the damping ring 270 is preferably larger than the outer diameter 262 of the bearing elements 231, 232. In addition, the inner diameter 263 of the damping ring 270 is preferably greater than or equal to the inner diameter 261 of the bearing elements 231, 232. Therefore, the damping ring 270 can axially support the bearing element 231 on its inner diameter 263.

[0042] According to one embodiment, the buffer ring 270 has a Figure 3 301) has an anti-rotation element 272 for forming an anti-rotation structure with the transmission housing 119. The anti-rotation element 272 preferably has at least one preferably radially oriented anti-rotation rib 271. The transmission housing 119 preferably has a receiving element 282 corresponding to the anti-rotation element 272. The receiving element 282 is preferably configured as a receiving portion.

[0043] Alternatively or optionally, the damping ring 270 has at least one groove 276 between its outer diameter 264 and inner diameter 263. Similarly, the transmission housing 119 preferably has at least one projection 284 on its section 292 on its inner side 285 facing the tool receptacle 150 for being arranged in the at least one groove 276 of the damping ring 270. The damping ring 270 preferably comprises a steel sheet and / or a plastic.

[0044] Figure 3 Shown arranged in Figure 2 The transmission housing 119 of the section 292 Figure 2 The buffer ring 270. Here, Figure 2 The damping ring 270 is shown schematically with an anti-rotation element 272 arranged on the outer circumference 301. As described above, the anti-rotation element 272 has at least one anti-rotation rib 271 which is preferably oriented radially.

[0045] As shown in the figure, twelve anti-torsion ribs 271 are arranged in the circumferential direction 305 of the buffer ring 270. However, any number of anti-torsion ribs 271 can be provided. The anti-torsion ribs 271 are preferably constructed in a rectangular shape. It should be noted that the anti-torsion ribs 271 can have any shape, such as a triangle, a polygon or a semicircle. As shown in the figure, the anti-torsion ribs 271 have the same radial height in the radial direction 202, however, the anti-torsion ribs 271 can also have different radial heights in the circumferential direction 305. Preferably, all anti-torsion ribs 271 have the same shape, however, the anti-torsion ribs 271 can also have different shapes in the circumferential direction 305.

[0046] also, Figure 3A receiving element 282 corresponding to the anti-rotation element 272 is shown in the section 292 of the transmission housing 119 for forming an anti-rotation structure between the damping ring 270 and the transmission housing 119. In addition, Figure 3 At least one groove 276 is shown arranged between the outer diameter 264 and the inner diameter 263 of the buffer ring 270. As shown, four grooves 276 are arranged in the circumferential direction 305 of the buffer ring 270, however, the buffer ring 270 can have any number of grooves 276. Each groove 276 has, for example, an arc-shaped section 311 and a semicircular section 312 on the side shown in the figure. Correspondingly, the section 292 or the protrusion 284 has an arc-shaped section 321 and a semicircular section 322 on the side shown in the figure. Similar to the anti-rotation element 272, the groove 276 can have any shape. Therefore, the groove 276 can be, for example, rectangular, polygonal, elliptical or circular. In addition, grooves 276 of different structures can also be formed in the circumferential direction 305 of the buffer ring 270.

[0047] Furthermore, the anti-torsion ribs 271 and the grooves 276 are arranged diametrically opposite to each other, but may also be arranged at irregular intervals in the circumferential direction 305. Furthermore, the anti-torsion ribs 271 may be arranged diametrically opposite to each other, while the grooves 276 are arranged at irregular intervals in the circumferential direction 305, or vice versa. As shown, the grooves 276 are arranged in the radial direction 202 between the anti-torsion ribs 271 and the inner diameter 263 of the buffer ring 270. However, the grooves 276 may also be arranged offset relative to the anti-torsion ribs 271 in the circumferential direction 305.

[0048] It should be noted that the buffer ring 270 may have an anti-rotation element 272 and / or at least one groove 276. Therefore, the buffer ring 270 may be configured with only the anti-rotation rib 271 or only the groove 276.

[0049] According to another embodiment, section 292 of transmission housing 119 may have an anti-rotation element 272 and / or at least one recess 276 , and damping ring 270 may have receiving elements 282 corresponding to anti-rotation element 272 and / or projections 284 associated with recess 276 .

[0050] Figure 4 Show Figure 2 and Figure 3 The buffer ring 270 has an anti-rotation element 272 and a groove 276 for Figures 1 to 3 The transmission housing 119 forms an anti-twist structure. Figure 4 The outer diameter 264 and the inner diameter 263 of the damping ring 270 are shown schematically.

[0051] Figure 5 Show Figures 1 to 3The section 292 of the transmission housing 119. Figure 5 Visually show the receiving Figures 2 to 4 The receiving element 282 of the anti-rotation element 272 of the buffer ring 270 and the protrusion 284 of the groove 276 assigned to the buffer ring 270. For simplicity and clarity, Figure 5 Only one of the four protrusions 284 shown is indicated by a reference numeral.

[0052] Figure 6 Show Figure 5 The section 292 of the transmission housing 119 has a cup-shaped base body 610 and an axially facing Figure 2 The tool receiving part 150 of the embodiment of the present invention is provided with a receiving element 282 and a projection 284 and a receiving part 296 for arranging at least one bearing element 231, 232. The projection 284 preferably forms an axial support for at least one bearing element 231, 232 that can be arranged in the receiving part 296, thereby preventing at least one bearing element 231, 232 from moving toward the drive motor 114 or to the left in the axial direction 102 of the transmission 118. For this purpose, the projection 284 closes the receiving part 296 in sections on its radial outer area.

Claims

1. A handheld power tool (100) comprising a tool receptacle (150) and a housing (110), in which a drive motor (114) and a transmission (118) are arranged, wherein: The transmission device (118) is equipped with a mechanical rotary impact mechanism (122) for impact-driving a tool receiving part (150), wherein the tool receiving part (150) is equipped with a receiving sleeve (299), wherein the transmission device (118) and the mechanical rotary impact mechanism (122) are arranged in a transmission device housing (119), wherein the mechanical rotary impact mechanism (122) has an impact body (210) and an anvil (220) equipped with the receiving sleeve (299), and wherein the receiving sleeve (299) is radially fixed to the receiving sleeve (299). The invention relates to a transmission device for a bearing element (231, 232) fixed in the transmission housing (119) and supported in a rotatable and axially movable manner, characterized in that it has a buffer ring (270), which is arranged axially between the anvil (220) and the bearing element (231, 232) in the transmission housing (119) facing the impact body (210) and at least in a region, wherein the buffer ring (270) has an inner diameter (263) that is smaller than the outer diameter (262) of the bearing element (231, 232).

2. The handheld power tool according to claim 1, characterized in that The outer diameter (264) of the buffer ring (270) is larger than the outer diameter (262) of the bearing elements (231, 232).

3. The handheld power tool according to claim 1 or 2, characterized in that: The inner diameter (263) of the buffer ring (270) is larger than the inner diameter (261) of the bearing elements (231, 232).

4. The hand-held power tool according to claim 1, characterized in that The buffer ring (270) has an anti-twist element (272) on its outer circumference (301) for forming an anti-twist structure.

5. The handheld power tool according to claim 4, characterized in that The anti-rotation element (272) has at least one anti-rotation rib (271), preferably a radially oriented anti-rotation rib.

6. The handheld power tool according to claim 4 or 5, characterized in that: The transmission housing (119) has a receiving element (282) corresponding to the anti-rotation element (272).

7. The hand-held power tool according to claim 1, characterized in that The buffer ring (270) has at least one groove (276) between its outer diameter (264) and its inner diameter (263).

8. The handheld power tool according to claim 7, characterized in that The transmission housing (119) has at least one projection (284) on its inner side (285) facing the tool receptacle (150) for being arranged in the at least one recess (276) of the damping ring (270).

9. The hand-held power tool according to claim 1, characterized in that At least two bearing elements (231, 232) are provided, which are in axial contact along the axis of rotation (201) of the tool receiving part (150).

10. The hand-held power tool according to claim 1, characterized in that The damping ring (270) comprises sheet steel and / or plastic.

Images