[f. FLY sb.2 + WHEEL.] A wheel with a heavy rim, attached to a revolving shaft, in order either to regulate the motion of the machinery, or to accumulate power. (Cf. FLY sb.2 5 c.)
[1782. Watt, Patent, in Muirhead, Mech. Invent. Watt III. 71. The heavy fly X X is put in motion by means of a pinion or smaller wheel Y fixed upon its axis.]
1784. Ibid., 105. The rod E … turns the fly wheel M M.
1809. Edin. Rev., XIII. Jan., 321. This engine had no fly-wheel, and went sluggishly and irregularly.
1862. Smiles, Engineers, III. 89. The engine was provided with a single cylinder six inches in diameter, with a flywheel working at one side to carry the crank over the dead points.
fig. 1876. T. Hardy, Hand Ethelb. (1890), 106. My dear mother, you will be necessary as a steadying power—a flywheel, in short, to the concern.
