Heat-dissipation component for handheld machine tool

Abstract

A handheld machine tool has a drive motor for driving a tool holder, in which a tool is able to be accommodated. In addition, a cam-action mechanism for generating a hammer function is provided, which includes a cam-action mechanism holder and a notched disk. The cam-action mechanism holder is in contact with a heat-dissipating component situated inside the housing.

Claims

1. A handheld machine tool, comprising: a tool holder to accommodate a tool; a drive motor to drive the tool holder; and a cam-action mechanism including a cam-action mechanism holder and a notched disk, wherein the cam-action mechanism holder is in contact with a heat-dissipating component situated inside a housing of the handheld machine tool, wherein the heat-dissipating component axially supports the cam-action mechanism holder and exerts an axial force thereon in an axial direction away from the tool holder towards the drive motor.

2. The hand-held machines tool as recited in claim 1, wherein the hand-held machine tool is a hammer drill.

3. The hand-held machine tool as recited in claim 1, wherein holding flanges are situated on a radial outside of the cam-action mechanism holder, on which the heat-dissipating component exerts an axial force.

4. The hand-held machine tool as recited in claim 1, wherein the heat-dissipating component is mounted on the housing in place relative to with the aid of affixation elements.

5. The hand-held machine tool as recited in claim 1, wherein the heat-dissipating component is configured in the form of a cup.

6. The hand-held machine tool as recited in claim 5, wherein the heat-dissipating component is fixed in place inside the housing of the handheld machine tool via a bottom of the cup.

7. The handheld machine tool as recited in claim 5, wherein the heat-dissipating component has a recess in a bottom of the cup in which the cam-action mechanism holder is accommodated.

8. The hand-held machine tool as recited in claim 5, wherein an open cup side of the heat-dissipating component faces the tool holder.

9. The hand-held machine tool as recited in claim 1, wherein the heat-dissipating component extends up to an end face of the housing adjacent to the tool holder.

10. The hand-held machine tool as recited in claim 1, wherein the heat-dissipating component is made of metal.

11. The hand-held machine tool as recited in claim 1, wherein the cam-action mechanism holder is situated adjacent to an end face of the housing facing the tool holder.

12. The hand-held machine tool as recited in claim 1, further comprising: at least one spindle bearing configured to support a drive spindle, the at least one spindle bearing being axially disposed inside the housing on a side of the cam-action mechanism holder facing away from the tool holder.

13. A handheld machine tool, comprising: a tool holder to accommodate a tool; a drive motor to drive the tool holder; and a cam-action mechanism including a cam-action mechanism holder and a notched disk, wherein the cam-action mechanism holder is in contact with a heat-dissipating component situated inside a housing of the handheld machine tool, wherein the heat-dissipating component axially supports the cam-action mechanism holder and exerts an axial force thereon, wherein at least one holding flange is situated on a radial outside of the cam-action mechanism holder, on which the heat-dissipating component rests and exerts an axial force in an axial direction away from the tool holder towards the drive motor.

14. A handheld machine tool, comprising: a tool holder to accommodate a tool; a drive motor to drive the tool holder; and a cam-action mechanism including a cam-action mechanism holder and a notched disk, wherein the cam-action mechanism holder is in contact with a heat-dissipating component situated inside a housing of the handheld machine tool, wherein the heat-dissipating component axially supports the cam-action mechanism holder and exerts an axial force thereon, wherein the cam-action mechanism holder includes at least one holding flange on a radial outside of the cam-action mechanism holder and the heat-dissipating component rests on the at least one holding flange such that the cam-action mechanism holder is mounted in place relative to the housing by an axial force exerted by the heat-dissipating component on the at least one holding flange.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic representation of a handheld machine tool.

(2) FIG. 2 shows the handheld machine tool in a section.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(3) Identical elements are provided with the same reference numerals in the figures.

(4) Handheld machine tool 1 shown in the figures is a battery-operated hammer drill and has a schematically represented electric drive motor 3 inside a housing 2; via a gear unit 4, preferably implemented as a planetary gearing and situated in a gear housing 4a, the drive motor drives a drive spindle 5 which supports a drill chuck 6 having a tool holder.

(5) As can be gathered from FIG. 2, drive spindle 5 is supported in the housing in rotatable manner via two spindle bearings 8 and 9. First spindle bearing 8, which sits at a greater axial distance from end face 2a, is attached to the housing, and second spindle bearing 9 is developed as floating bearing and held so as to be displaceable in the axial direction. Second spindle bearing 9, which lies closer to end face 2a, is axially supported on first spindle bearing 8 via a spring element 10.

(6) To realize a hammer function, handheld machine tool 1 is provided with a cam-action mechanism 11, which encompasses a cam-action mechanism holder 12 and a notched disk 13. Cam-action mechanism holder 12 is permanently joined to the gear housing. Drive spindle 5 is supported in a manner that allows it to be displaced relative to gear housing 4a in the axial direction. Annular notched disk 13 is fixedly connected to drive spindle 5; it is situated within gear housing 4a and is able to rotate inside gear housing 4a. On the end face facing the notched disk, cam-action mechanism holder 12 is provided with a sinusoidal or saw-tooth-like wave profile 14 rotating in the circumferential direction; this profile 14 comes into contact with a latching cam on notched disk 13 when cam-action mechanism holder 12 and notched disk 13 axially approach each other, so that rotating notched disk 13 probes the contour of wave profile 14 on cam-action mechanism holder 12 and thereby produces an axial relative motion that corresponds to the wave profile. The contact between cam-action mechanism holder 12 and notched disk 13 takes place when the tool in tool holder 7 is pressed against a workpiece to be processed, so that components 12 and 13 of cam-action mechanism 11 approach each other counter to the force of spring element 10.

(7) A cup-shaped heat-dissipating component 15, which is mounted on the housing and is in contact with cam-action mechanism holder 12, is integrated into gear housing 4a. Frictional heat produced by the relative movement between notched disk 13 and cam-action mechanism holder 12 is shunted to the outside by way of heat-dissipating component 15.

(8) Heat-dissipating component 15 has a cup bottom 16, into which a recess is introduced which wraps around cam-action mechanism holder 12. The wall delimiting the central recess in cup bottom 16 rests against the lateral surface of cam-action mechanism holder 12. In addition, the part of the wall that delimits the recess supports cam-action mechanism holder 12 in the cup bottom in that the wall is resting against a holding flange or against a plurality of holding flanges 19 distributed across the periphery, which are integrally formed with cam-action mechanism holder 12. In the process, heat-dissipating component 15 exerts an axial force on cam-action mechanism holder 12 and thereby fixes it in position inside the housing. Holding flanges 19 overlap second spindle bearing 9 in the axial direction, and the annular body of cam-action mechanism holder 12 carrying holding flanges 19 is situated between second spindle bearing 9 and end face 2a.

(9) In the axial direction, cup wall 17 of heat-dissipating component 15 extends toward frontal end face 2a, which faces drill chuck 6, but lies at an axial distance from drill chuck 6. A radially outwardly projecting lip 18 on cup wall 17 is situated in direct proximity to end face 2a. When drill chuck 6 is rotating, an air flow is generated in the annular gap between the drill chuck and end face 2a, which helps in dissipating the heat to the environment.

(10) Heat-dissipating component 15 is held inside housing 2 with the aid of affixation elements in the form of screws 20. Screws 20 are guided through cup bottom 16, parallel to the central recess, and anchor heat-dissipating component 15 at sections of the gear housing. Screws 20 are also able to interconnect different parts of the gear or the gear housing.

(11) Cup-shaped heat-dissipating component 15 is made of a metal or some other material having high thermal conductivity.