61. Q. How can it be known if an eccentric has slipped on the axle?

A. By the uneven exhaust of the engine and a thorough inspection to

determine the cause.

62. Q. Having determined which eccentric has slipped, how should it be

reset?

A. Place the engine on the center on disabled side and if a back-up

eccentric has slipped, would place the reverse lever in full forward

gear and mark the valve stem flush with the gland; then place the

reverse lever in full back gear and move the slipped eccentric until the

mark on the stem returns to its original position, taking notice that

the throw of the eccentric is on the other side of the axle from the

go-ahead eccentric used as a marker, and tighten up set-screws. To set a

go-ahead eccentric, use the back-up one on that side for the marker. If

the eccentric had been keyed on, would move the cam until the key-way in

the axle came in line with the slot in the cam. Knowing the position of

the eccentric in relation to the crank pin, an inspection would show

where it belongs. The eccentrics are usually opposite the third spoke in

the driving wheel from the pin, sometimes ahead of the pin, in other

cases back of the pin, depending on whether it is an inside or outside

admission valve, a go-ahead or back-up eccentric.

The Traveling Engineers' Association to Improve the Locomotive Engine Service of American Railroads Examination Questions and Answers for Firemen for Promotion and New Men for Employment · 第 148 / 436 题