| 释义 |
dedendum Mech.|diːˈdɛndəm|
[L., neut. gerundive of dēdere to give up, surrender.]
a. ‘That part of the tooth of a cog-wheel or gear which is inside the pitch-circle and is intercepted between the pitch-line and the circle which limits all the roots of the teeth and the spaces between them’ (Cent. Dict. Suppl., 1909). Also attrib.
b. (See quot. 1958.)
1901Internat. Libr. Technol. II. (Gear-Cutting) §17. 7 A tooth is composed of two parts, the addendum, or part outside the pitch circle, and the part inside, which is called either the root or the dedendum. 1909N. Hawkins Mech. Dict. 185/2 The dedendum circle is the circle within the pitch circle, to which the bottom of each tooth extends. 1925Berard & Waters Elem. Machine Design x. 180 The bottoms of the grooves are limited by a root or dedendum circle, distant from the pitch circle by an amount called the dedendum. 1949E. Buckingham Analytical Mech. Gears xii. 256 We shall use a constant axial pitch of 1 in... This would give us the following thread proportions:..Dedendum 0·3247 [in.]. 1958Chambers's Techn. Dict. Add. 971/1 Dedendum, radial distance between the pitch and minor cylinders of an external screw thread; radial distance between the major and pitch cylinders of an internal thread. 1961P. S. Houghton Gears (ed. 2) i. 6 The dedendum of spur, helical and worm gearing is the radial distance of the tooth measuring from the pitch circle to the bottom of the tooth space. For a bevel gear it is the depth of the tooth space below the pitch circle measuring along the back cone generator or edge angle. |