DE7609459U1 - COMMUTING ELECTRIC MOTOR - Google Patents

Description

STANLEY POWER TOOLS LIMITED, Cramiington, Northumberland

(Great Britain)

Commutating electric motor

The innovation concerns a commutating electric motor (DC-AC or all-current motor) and in particular the radio and television screening of communicating electric motors.

Usually a capacitor is used to suppress interference in a commutating electric motor. However, in certain cases Applications, for example, in portable devices powered by commutating electric motors, the capacitor be quite large and take up a disproportionately large amount of space in the device.

It is the task of the innovation to provide acceptable radio and television interference suppression for a commutating electric motor

67- (28855) MaF

7603459 07/29/76

obtained, either without using a capacitor I or when using a smaller capacitor than previously «usual. I.

The innovation is based on the knowledge that at commu- |

electric motors are a component that is essential to f

Radio and television interference contributes because of the f

disturbances caused by the commutator, the steel V / elle of the 1st

Engine is. This steel shaft that is electrically conductive i

and protrudes through the commutator, causes a transfer of the j

Disturbances outside the engine. \

The task is with a commutating electric motor

newly solved by a rotor, rotor or armature |

with windings and a commutator 'on a shaft |

by the commutator and the windings 1

protrudes, with at least a part of the wave, which through the commu- 1

tator and protrudes through the windings, completely from a 1

electrically insulating hard material consists of at least J

electrical disturbances partly generated by the commutator |

attenuates or suppresses. The wave lenn another metal ₄

part included, z. B. made of steel, the commutator and 1

the windings is spaced apart, the hard or tough!

Material is poured or injected around the metal part and \ keyed to for transmitting torque.

The hard or tough material is advantageously a glass fiber-filled synthetic resin, which is preferably curable,
such as a glass fiber-filled polyimide resin, for example sold under the trade name Kinel.

The innovation is shown on the basis of the drawing

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Ii ι II i
ι 1
I 1 1 closer explained. It show: Γ - 3 - (ο posed EXAMPLE EXAMPLE

Pig. 1 the section A-A according to FIG. 2 of a commutating Electric motor according to the innovation;

FIG. 2 shows the electric motor according to FIG. 1 in a plan view; FIG. FIG. J5 shows the electric motor according to FIG. 1 in a front view; FIG.

FIG. 4 enlarges part of that shown in a bordered manner in FIG Electric motor;

Fig. 5 is an enlarged partial section of the rotor, rotor or Armature shaft of the electric motor of FIGS. 1 to 4 with rotor, rotor or armature lamellas before winding windings and before connecting them to the commutator;

6 shows one of the rotor, rotor or armature lamellae;

7 shows the rotor, runner or armature of the in side view Motor according to FIG. 1 after winding the winding and connecting it to the commutator.

The electric motor shown in the drawing has, except for the. Training '' according to Figures 5 and 6, conventional structure. The motor contains a rotor, rotor or armature, rotor 1 for short, a wound stator or field coil 2 _} , a housing 2 for a rear bearing 12, two brushes 4, an end shield 5 for a front bearing 6, a housing 7 for the front bearing 6, two clamping screws 8 for clamping or clamping together the housing 3 * of the stator and the housing 7, two clamping screws 9 for attaching a receiving plate or clamp 15 that accommodates the rear bearing 12 to the housing 3, a retaining ring 10 for the

en

rear bearing 12, a ⁷ lubrication guard 11 for the rear

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• f * I

t t ■

* I I I

Bearing 12, brush holder caps 13, a nameplate 14, two spring washers 16 for the two clamping screws 8, a washer 17 for the front bearing 16, another nameplate 18 and / wire insulation shield 19 for the rotor 1.

The rotor 1 contains a commutator la, in the usual Way with the brushes 4 is in contact. The rotor 1 is mounted on a shaft Ib which is driven by the commutator la and also protrudes through windings Ic on the rotor 1. The windings Ic contain lamellas Id and also restraint or Barrier strips Ie, so-called upper webs, which the windings Ic hold back in slots Id 'in the lamellae Id. Inside is located between the commutator Ib and the windings Ic a felt disc If.

According to Fig. 5, the shaft Ib consists of two parts, namely

a- {-rtfävkcszä * f 4- e A-t nam ΓΠα4Ί 1VkI one

itui uuai cu r uij j.iiu. \ x —xiUiio ulmx'Zi, uciopiciflwciBC Ucx * nanucid designation Kinel, and a further part Ib "made of steel, with the part Ib 'made of filled synthetic resin around the part Ib" cast from steel or injected 1st. The part Ib ¹ made of filled synthetic resin is wedged by means of a transverse groove Ig in the part Ib ″ made of steel for torque transmission and is wedged with three equally angularly spaced keyways in the circumference of the axial bore lh of the lamellae Id the lamellas Id are stacked in a stack (cf. GB-PS 1 4o6 645). The stack of lamellas Id and the shaft part Id "made of steel are then introduced into an injection mold (not shown) and glass fiber-filled polyimide resin is injected into the mold to form it of the shaft part Ib ', the one with the transverse groove Ig in the shaft part Ib "made of steel

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and is wedged with the keyways in the sipes Id. Then, the rotor windings Ic ^ backing strip Ie _3, the felt If the commutator la and the insulating shield are joined together as in a conventional rotor or armature, wobeijdie windings _Ic% are conventionally connected to the commutator la as, and with the rotor 1 or anchor is conventionally sealed with a synthetic resin.

The shaft part Ib ¹ made of the electrically insulating, glass fiber-filled, thermosetting synthetic resin causes · by ,, that it protrudes through the commutator la and also through the windings Ic and the rotor lamellae Id that; at least partially electrical disturbances which are caused by the commutator la and the brushes 4 are attenuated or blocked. Even if the attenuation cannot be sufficient to be able to completely do without a capacitor for suppressing radio and television interference, so

one that would be the case with an all steel shaft is to be used. For example, radio and television interference suppression has been improved in a motor designed according to the invention with a capacitor of only 0.15 / UF compared to a similar motor but with an all steel shaft and capacitor with 0.20 / UF.

The reason why the shaft Ib has a steel part Ib " contains is that steel is more wear-resistant than glass fiber-filled thermosetting resin for transmitting an output from the engine to the load, for example a (not shown) working or wearing part

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for example a power device or tool.

It is to be expected that assembly line manufactured innovations according to commuting electric motors better and more uniform Radio and television interference suppression properties than conventional motors of a similar design; H. those that differ only in that they have a shaft made entirely of steel.

The innovation is also applicable to a permanent magnet commutator motor, for example a commutating or Commutator motor with armature corresponding to FIGS. 5 and 6 but with permanent magnets instead of the stator winding or the field coil of the motor shown.

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Claims (3)

- 7 claims for protection 1. Commutating electric motor with a rotor, armature or armature of the windings and one loading on a shaft; has solid commutator, which by the commutator and: protrudes through the windings, ■ characterized by \ that at least a part (Ib ¹ ) of the shaft (Ib), which protrudes duroh the commutator (la) and through the windings (Ic), consists entirely of an electrically insulating hard material, at least the electrical interference caused by the commutator (la) partially dampens. 2. Electric motor according to claim 1, characterized in that the shaft (Ib) another part (lb ") made of metal, such as steel at a distance from the commutator (la) and to the windings (Ic), the hard material (Ib ') around the metal part (Ib ") is cast and is wedged with this (groove Ig) for torque transmission. 3. Electric motor according to claim 1 or 2, characterized in that the hard material is a glass fiber-filled, in particular thermosetting, synthetic resin. 7609459 07/29/76