Rotating Loosening Mechanism of a Nut Connecting a Rotary Disk Under Rotating-Bending Force

[+] Author and Article Information
Yasuo Fujioka

Material Engineering Division 3, Toyota Motor Corporation, 1200, Misyuku, Susono, Shizuoka, 410-1193, Japanfujioka@y.tec.toyota.co.jp

Tomotsugu Sakai

Training & Training Development Division, Toyota Techno Service Corporation, 5-5, Nishimachi, Toyota, Aichi, 470-0025, Japantomsakai@nano.tec.toyota.co.jp

J. Mech. Des 127(6), 1191-1197 (Feb 27, 2005) (7 pages) doi:10.1115/1.2049087 History: Received July 18, 2004; Revised February 27, 2005

Structures composed of a rotary disk and a shaft, which are fastened with bolts and nuts having tapered bearing surfaces, are loaded with a rotating-bending force. Upon investigation, two rotating mechanisms of the nut were derived. In one mechanism a high-pressure contact area is formed at the nearest loading point on threads and bearing surfaces. This leads to a difference in the curvature radii between the bearing surface of the disk and that of the nut. During the revolution of the disk, two friction torques occur in opposite directions on the bearing surface and the threads, respectively. The relative rotating direction of the nut is dominated by the greater torque. The other mechanism is due to the eccentricities caused by dimensional errors of the bolt, nut, and disk. By combining the two mechanisms, the rotations of the nuts either cause a loosening or tightening after many revolutions of the disk.

Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 9

Phenomenon of the relative rotation of the nut during a single complete rotation of the rotary disk

Grahic Jump Location
Figure 1

Schematic diagram of the specimen

Grahic Jump Location
Figure 2

Radii around a tapered bearing surface (a cross section perpendicular to the bolt axis)

Grahic Jump Location
Figure 3

Deformation image of the bearing surface around a bolt and nut

Grahic Jump Location
Figure 6

Experimental results of relative rotation of the nuts under rotating-bending cyclic loading

Grahic Jump Location
Figure 7

Dimensions of radii

Grahic Jump Location
Figure 8

Calculation results of the relative rotation of nuts under a rotating-bending force

Grahic Jump Location
Figure 10

Relation among the load direction, high-pressure contact area position, and the rotating direction of the nut

Grahic Jump Location
Figure 11

Experimental results of the relative rotation of the nut during a single complete rotation of the rotary disk

Grahic Jump Location
Figure 12

Deformations by the external load on the bearing surfaces

Grahic Jump Location
Figure 13

Slip direction due to the external load

Grahic Jump Location
Figure 14

Direction of correction factors and modified values

Grahic Jump Location
Figure 4

Direction of a nut rotation (the disk rotates clockwise and the bolt is fixed to the disk)

Grahic Jump Location
Figure 5

Dimensions of the nut and rotary disk



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In