GB1314458A - Detecting electrically conductive particles - Google Patents

Abstract

1314458 Detecting electrically conductive particles J N SMITH 21 Nov 1970 55452/70 Addition to 1195562 Heading G1N [Also in Division F2] In a device for detecting electrically conductive particles resulting from wear in a part consisting of electrically conductive material e.g. a bearing in contact with a lubrication system the particles are caused to be deposited non-magnetically on a surface such that a predetermined deposit causes contacts to be bridged and a circuit activated. The detector 511 positioned at the bottom of the unit Fig.1 includes an electrically conductive body 522, Fig. 3 in through-bores of which are mounted an insulated central pin 536 and six arcuately spaced insulated contact pins 540, Fig.4 (not shown). The top ends of pins 540 and their insulating sleeves 542 are exposed at the top surface of body 522 and together with the top surface of body 522 are shaped so that each pin 540 is surrounded by a V-shaped cross-section annular groove 548 Fig. 5 (not shown) to define particle receiving surfaces. In operation the lubrication fluid enters the unit tangentially at 500 and particles of conductive material gravitate from the fluid into the annular grooves 548. When the grooves are full an electrical contact is made between a pin 540 and body 522. The six contact elements 540 are each connected in series with a respective resistor and the combination connected in parallel via a common variable resistor to a relay, Fig. 10 (not shown) which is operated only when all the six gaps are closed to energize a lamp. A further relay may be used so that the first relay is operated when some of the contact gaps are bridged and the further relay operated when all are bridged. A "high level" warning lamp is operated when the conductive material builds up to prongs 533 on an annular contact ring mounted on insulator 528 and connected to central pin 536 by lead 534. Figs. 7, 8, 9 (not shown) show alternative arrangements of the particle collecting unit, Fig. 9 (not shown) including a by-pass control valve so that the unit is operated only when required. If a plurality of branch conduits of the lubricating system flow into a common conduit the branch conduits may each be provided with a detector unit as described above or in the parent and the common conduit has a detector unit having more contact elements. When the common conduit detector is operated the branch detectors may be operated to locate in which branch the particles are flowing.