A Newly Designed Portable Wear Testing Machine

A newly designed portable wear testing machine is presented in this paper. The spherical rotating wheel of this machine is impressed on the flat surface of the test piece under the load which is increased in proportion to the increase of the contact area between the rotating wheel and the test piece, and therefore the mean contact pressure is constant notwithstanding the increase of the depth of the impression. The load is applied by means of an electro-magnet, and hence the more deelply the wheel is lowered into the wear track of the test piece, the less the gap of the electromagnet and so the heavier the load. It is investigated theoretically and experimantally that the pressure varies little during test. The wear amount is estimated by measuring diameter of the wear impression microscopically. Microwear volume can be detected by the machine within a short time. The machine is portable (about 6 kg) and can be fixed on a large test piece.