CZ243895A3 - Collecting ring, optionally commutator - Google Patents

Abstract

Slip ring and commutator consists of a slip ring and commutator pressed compsn. esp. duroplast, contg. a filler, as carrier for a slip ring and lamellar surface ground from contacts. The novelty is that the filler used is one separated from asbestos-free low molecular cpds. at excess temp. loads. Pref. the filler contains H2O separated Mg(OH)2 at ca. 400 degrees C. Wollastonite filler is also added in amt. of 7-70%. The wollastonite filler has a needle-like structure. Glass fibres or glass balls are opt. added.

Description

£ blast_technics

The invention relates to a slip ring or commutator for a slip ring or commutator motor, with a slip ring or collector molding compound comprising a filler, in particular a thermosetting molding compound, as a carrier of the slip surface of the slip rings or contact plates.

BACKGROUND OF THE INVENTION

A commutator of this kind is known, for example, from ΞΡ-Α1-0 482 235. The commutator motor is supplied with brushes by sliding on the slip rings or on the stator side. lamellas, mounted on the outer periphery, radially inside, the rotor shaft, the support body. This usually consists of a molding material, in particular a thermoset, to which fillers are added to increase its volume. It is known to admix asbestos fibers as a filler, which are characterized by high thermal stability, mechanical strength, a good bonding capability with a high specific weight at an apparent coefficient of expansion. However, they are undesirable due to their poor bio-tolerance especially to make cancer stimulating. As a rule, they are even forbidden by the legislature.

Attempts have been made to replace asbestos as a filler with glass fibers. glass spheres, that have a significant drawback due to slight resiliency .jejich the company, their low temperature resistance as well ^a bad coupling with the other options' molding compound.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a substitute mass for asbestos which, with good physiological compatibility, still exhibits particularly advantageous material properties with asbestos.

Particularly important is the resistance to short-term temperature overloads; such thermal overloads can occur in particular during thermal theming of the winding wires with segmented commutator hooks or in the case of thermal winding. slip rings or blocking test of the finished engine. In addition, the replacement material is to be used without difficulty in slip rings or commutators during their mass production.

The solution to this object consists in the slip ring or commutator of the above-mentioned type in that the filler is an asbestos-free additive which cleaves off at the thermal overloads of the low molecular weight compound while absorbing energy; in particular, according to the development of the invention, magnesium hydroxide, preferably leaving at about 400 ° C water (H 2 O), is added to increase the thermal compatibility of the filler.

Surprisingly, it has been found that the additive according to the invention can produce a temperature buffer with good mechanical and insulating characteristics with low coefficient of expansion.

According to a further development of the invention, it is admixed as v / ollastonite filler, preferably a needle-like structure, the proportion of which is about 7% to 70% of the total (100%) of the filler; The length / needle ratio of the needles of the filler formed by the wollastonite needle structure is preferably in the range between 30: 1 to 35: 1.

As a further proportion of filler according to a further development of the invention, it is envisaged to add glass fibers and / or glass beads.

V / ollastonite is calcium silicate (CaSiO ^) and belongs to a group of naturally occurring chain-structured silicates, with the chain direction corresponding to four times the silicon compound (SiO ^) of the elongation of needle-structured wollastonite particles. strength, the tensile strength and the modulus of elasticity being substantially higher than the phenolic resin assumed for the molding composition. It has been shown that against the filler in the form of fiberglass or. Addition of magnesium hydroxide or glass bead wollastite filler, both higher thermal stability and higher specific gravity of the filler, as well as high thermal conductivity and good resistance to welding temperatures with high thermal stability when welding commutator hooks, as well as low shrinkage with low expansion coefficient.

The properties are an affection before it is a very fast human plio approximately 100 days to 60,000 days at

These advantageous specificities are associated with the high physiologically tolerated additives to the molding compound, the removability of the fibers which have been formed within 8 to 15 days compared to the glass fibers and possibly 40,000 asbestos materials.

By preferably treating the surface of the wollastonite particles, i.e., providing them with a layer of silane (SiH4), in particular epoxisilane, aminosilane and methacrylsilane, the bonding ability between the phenolocular resin arranged as the carrier material and the filler can be improved.

Claims (5)

PATENT CLAIMS A slip ring or commutator for a slip ring or commutator motor, comprising a slip ring or collector molding compound comprising a filler, in particular a thermosetting molding compound, as a carrier for the slip surface of the slip rings or contact plates, characterized in that the additive forms a splitting filler at low molecular weight compound energy absorption. asbestos temperature buckle present Slip ring or commutator according to claim 1, characterized in that the additive is magnesium hydroxide (Mg (OH) 2), which cleaves in particular at ca. 400 ° C water (HgO). Slip ring or commutator according to claim 1 and / or 2, characterized in that the further filler additive is wollastonite, whose proportion in the total amount of filler is 1% to 70%. A slip ring or commutator according to claim 3, characterized in that the wollase-tonicite filler has a needle-like structure. * Collector as claimed in any of the preceding claims, characterized in that the filler ring or commutator according to any one of claims 1 to 4, characterized in that it consists of glass fibers and / or glass beads.