US-20260124732-A1 - Hand-held power tool

US20260124732A1US 20260124732 A1US20260124732 A1US 20260124732A1US-20260124732-A1

Abstract

A hand-held power tool ( 1 ) having a drive device ( 5 ) by which a tool that is able to be operatively connected to the power tool ( 1 ) is able to be actuated via a transmission device ( 7 ) having a transmission housing ( 9 ). A housing device ( 3 ) is provided, within which the drive device ( 5 ), having a rotor ( 31 ) and a stator ( 29 ), and the transmission device ( 7 ) are arranged. An electrically conductive connecting device ( 40 ) is provided within the power tool ( 1 ). The connecting device ( 40 ) electrically conductively connects the stator ( 29 ) of the drive device ( 5 ) to the transmission housing ( 9 ).

Inventors

Wolfgang Ludwig
Michael Morgenstern
Michael Kögel

Assignees

HILTI AKTIENGESELLSCHAFT

Dates

Publication Date: 20260507
Application Date: 20221109
Priority Date: 20211123

Claims (15)

1 - 11 . (canceled)
12 . A hand-held power tool comprising: a drive having a rotor and a stator, a tool operatively connectable to the power tool via the drive and actuatable via a transmission having a transmission housing; a housing, the drive and the transmission being arranged in the housing; and an electrically conductive connector electrically conductively connecting the stator of the drive to the transmission housing.
13 . The hand-held power tool as recited in claim 12 wherein the connector is operatively connectable to a housing element of the housing.
14 . The hand-held power tool as recited in claim 12 wherein the connector has a first connecting region for cooperating with the stator, wherein the first connecting region is embodied with at least one resilient region.
15 . The hand-held power tool as recited in claim 14 wherein the at least one resilient region includes two resilient regions.
16 . The hand-held power tool as recited in claim 12 wherein the connector has a second connecting region for cooperating with the transmission housing, wherein the second connecting region is embodied with at least one resilient region.
17 . The hand-held power tool as recited in claim 16 wherein the at least one resilient region includes two resilient regions.
18 . The hand-held power tool as recited in claim 16 wherein the second connecting region is positioned so as to be angled outwards in a radial direction in a region facing forwards in a longitudinal direction of the power tool in an assembled state of the power tool.
19 . The hand-held power tool as recited in claim 12 wherein the connector has resilient regions and cooperates loosely with the stator and the transmission housing, respectively, via the resilient regions in an assembled state of the power tool.
20 . The hand-held power tool as recited in claim 12 wherein the connector has, between a first connecting region for cooperating with the stator and a second connecting region for cooperating with the transmission housing, a supporting region supported on an element of the power tool in an assembled state of the power tool.
21 . The hand-held power tool as recited in claim 13 wherein the housing element of the housing has at least one contact region for positioning the connector.
22 . The hand-held power tool as recited in claim 12 wherein the connector is embodied with an electrically conductive cable connected to the stator at one end and to the transmission housing at the other end.
23 . The hand-held power tool as recited in claim 12 wherein the connector is formed by an electrically conductive coating.
24 . The hand-held power tool as recited in claim 23 wherein the coating is an electrolytic coating of an inner wall of the housing element, wherein a housing element of the housing has a coating region is connected both to the stator and to the transmission housing.
25 . The hand-held power tool as recited in claim 12 wherein the housing has two lateral housing shells and a front housing element connected releasably to the housing shells.

Description

The invention relates to a hand-held power tool having a drive device by means of which a tool that is able to be operatively connected to the power tool is able to be actuated via a transmission device having a transmission housing. BACKGROUND US 2019/0075639 A1, for example, discloses an electric power tool, which has a housing and a motor, wherein the motor, having a rotor, is arranged and held in the housing and is driven by a power source. SUMMARY OF THE INVENTION During operation of the electric power tool, voltage differences can arise between different components of the electric power tool, and these can induce electric fields which in turn can disturb an electronic system or a control device. In order to reduce such voltage differences, a wire is provided in US 2019/0075639 A1, which is electrically connected between the rotor and a connector of the power source. By means of the wire, electrostatic charges that are induced for example by a fan can be dissipated and voltage differences reduced. Electrostatically charged plastics parts cause large voltage differences and possibly discharges, which can damage the electronic components. In the solution of the 639 publication, a long distance within the electric power tool needs to be bridged by the wire, since the rotor and the voltage source are arranged in regions of the electric power tool that are far away from one another. It can be problematic to guide the wire on account of the available spatial conditions. In addition, the long wiring can possibly have an undesired influence on an air flow within the housing. Therefore, it is an object of the present invention to create a hand-held power tool in which the risk of the occurrence of electric fields, which can cause disturbances in particular of an electronic system or a control device, is reduced in a structurally simple manner that is favourable in terms of installation space. Therefore, a hand-held power tool having a drive device is provided, wherein, by means of the drive device, a tool that is able to be operatively connected to the power tool is able to be actuated via a transmission device having a transmission housing, wherein a housing device is provided, within which the drive device, having a rotor and a stator, and the transmission device are arranged, and wherein an electrically conductive connecting device is provided, in particular for reducing voltage differences, within the power tool. The invention proposes that the connecting device electrically conductively connects a stator of the drive device to the transmission housing. A hand-held power tool embodied according to the invention, which may be embodied for example as a power screwdriver, as an impact screwdriver, as a chipping machine, as an angle grinder, as a sawing machine or the like, has the advantage that, in a cost-effective manner optimized in terms of installation space, voltage differences that arise during operation between different components are advantageously low as a result of the provision of the connecting device and thus the risk of an electronic system or control device being disturbed by electric fields is advantageously low. The stator of the drive device embodied as an electric motor is preferably arranged in the spatial vicinity of the in particular metallic transmission housing, such that the connecting device takes up only little installation space within the housing device of the hand-held power tool. The risk of an air flow provided for example for cooling being undesirably influenced by the connecting device is also low as a result. Voltage differences between individual components of the hand-held power tool can arise in particular through components that conduct high voltage in operation or through a fan. During the operation of a hand-held power tool embodied according to the invention, advantageously no undesirably large electrostatic charges in particular in plastics parts arise, and so discharges that could result in damage to electronic component are reliably prevented. The connecting device is conductive and embodied in particular with metal, for example steel, and cooperates with the stator and transmission housing, which are likewise embodied with a conductive material. In principle, the connecting device can also be embodied with other suitable conductive materials, however. The connecting device is preferably not fixedly connected to the transmission housing and/or the stator. In this case, it is in particular advantageous when the connecting device is able to be operatively connected to, in particular brought releasably into engagement with a housing element of the housing device and is preferably held on the housing element. To cooperate with the connecting device, the housing element can have for example ribs or the like, such that the connecting device is easily held and/or positioned on the housing element and is also able to be assembled together with the housing element. In one