SK283415B6 - Slip ring or commutator motor - Google Patents

Abstract

Wollastonite (CaSiO3) with a structure in the form of needles is added as a filler to the phenol resin moulding compound for the supporting body of the slip rings and of the commutator laminates in order to produce an asbestos-free slip ring arrangement and commutator arrangement.

Description

Technical field

The invention relates to an annular motor or a commutator motor according to the general concept of claim 1; such a commutator motor is known e.g. from EP-A1-0 482 235.

BACKGROUND OF THE INVENTION

The slip rings, or lamellas, in the case of a ring anchor motor or a commutator motor for supplying the rotor with a current brushed on the stator side, are held on the outer periphery of the support body fixed radially inside the rotor shaft. phenolic resin mass, and to which fillers are attached as stretching material. It is known to admix as a filler asbestos fibers, which are characterized by high thermal stability, mechanical strength, good bonding ability and high filling density, but because of their low biocompatibility they are undesirable, even prohibited by lawmakers.

Glass fiber or glass bead fillers have been tried to fully or partially replace asbestos, but due mainly to their low elasticity, their non-existent water regime, their low resistance to welding temperatures as well as their poor bonding capacity to other presses, possibly to the copper segments of the slip ring or the slats, and due to their large coefficient of expansion, did not lead to the desired successes.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a substitute filler for asbestos which, when well tolerated, switches the asbestos-exhibited specific advantageous material properties and, with respect to its consumption, also applies to ring anchor or commutator motors manufactured as mass products on a mass scale.

This task is achieved in the case of a ring anchor motor or a commutator motor of the above-mentioned type by admixing the molded mass as a wollastonite with a needle-like structure in the form of naturally occurring silicate having a chain structure in a proportion of approximately 7% to 70% (100%). The ratio of the length and thickness of the needles of the wollastonite moiety with the needle-like structure in the filler ranges from 30: 1 to 35: 1.

The remaining filler is preferably constituted by an appropriate addition of glass fibers and / or glass beads.

Wollastonite is calcium silicate (CaSiO ₃ ) and belongs to a group of naturally occurring chain-structured silicates, the direction of the tetrahedron (SiO ₄ ) chains corresponding to the longitudinal extension of the needle-like wollastonite particles. The crystallographic property of wollastonite results in a high mechanical strength, while the tensile strength and the modulus of elasticity are significantly higher than for the phenolic resin planned for the molded mass. Surprisingly, it has been found that wollastonite filler can also provide not only high thermal stability and high fill density, but also a high specific thermal conductivity and good temperature resistance at low expansion coefficients compared to the substitute fillers in the form of glass fibers or glass beads. welding with high thermal stability when welding a commutator hook, as well as low contraction and low expansion coefficient.

These advantageous specific properties are associated with high biocompatibility due to the rapid degradability of the fibers penetrated into the human lungs within 8 to 15 days compared to a time interval of about 100 days for glass fibers or 40,000 to 60,000 days for asbestos hitherto used. materials.

By advantageously treating the surface of the wollastonite particles with a silane protective layer, in particular epoxy, amino and methacrylsilanes, it is possible in particular to improve the bonding ability between the resin matrix of the phenolic resin molded mass intended for the support body and the filler.

Claims (5)

PATENT CLAIMS 1. An annular motor or a commutator motor with a compression mass of a slip ring or collector, in particular a compression mass of phenolic resin containing a filler, as a carrier of the slip-ring surface or of a lamellar surface abraded by contacts, characterized by wollastonite filler with acicular structure. naturally occurring chain structure silicates having a proportion of about 7% to 70% of the total filler content. An annular motor or commutator motor according to claim 1, characterized in that the ratio of the length and thickness (d: h) of the needles of the wollastonite filler with the needle structure is in the range of 30: 1 to 35: 1. Ring-ring motor or commutator motor according to one of claims 1 and 2, characterized by a wollastonite filler with a pre-treated slurry. Ring-ring motor or commutator motor according to claim 3, characterized by a silanizing protective layer of wollastonite filler. Ring-ring motor or commutator motor according to one of Claims 1 to 4, characterized by an additional filler in the form of glass fibers and / or glass beads.