Electric motor for hand-held power tool

Abstract

The invention relates to an electric motor (1) of a hand-held power tool (2) operated at alternating voltage, comprising a stator (6) having a plurality of windings (9) which are accommodated in a laminated stator core (10) and are substantially electrically insulated from each other, in which a rotor (7) is mounted so as to be rotatable about an axis of rotation (8), wherein the rotor (7) has a rotor shaft (11) on which a rotor lamination stack (12) having a plurality of permanent magnets (13) is held, which rotor lamination stack is electrically insulated from the rotor shaft (11), characterized in that the stator (6) is surrounded by a motor housing (15), which is electrically insulated from a winding (9) of the stator (6), an electrical additional insulation (16) is formed between the motor housing (15) and the rotor shaft (11).

Description

technical field [0001] The invention relates to an electric motor of a hand-held power tool operated with alternating voltage, which has a stator with a plurality of windings which are accommodated in the stator lamination stack and are substantially electrically insulated with respect to the stator lamination stack. , in the stator lamination stack, the rotor is rotatably mounted about the axis of rotation, wherein the rotor has a rotor shaft on which the rotor lamination stack with a plurality of permanent magnets is held. Background technique [0002] Electric motors of this type, also known as EC-motors or brushless electronically commutated electric motors, have long been known from the prior art, for example from DE 10 2010 031 399 A1. In the case of such EC-motors, which are often used in hand-operated or portable power tools with a wired connection, suitable actuation produces a rotating magnetic field in the stator, which drives the rotor in order to thereby drive t...

AI Technical Summary

Problems solved by technology

[0003] When using such grid-operated EC electric motors in hand-held power tools (conductive metal dust or particles are present during their use), for example for angle grinders in metal construction, however, there are The problem described above is that if these dusts or particles enter the hand-held power tool with the cooling air and then enter the electric motor, the risk of a short circuit increases due to the high mains voltage

There is then the risk that the electric motor is damaged or that current is transmitted via the rotor shaft to the housing, which is associated with a risk of injury to the user.

Images