Page 276 - Modular design for machine tools

Engineering Design Fundamentals and Single Flat Joint Characteristics 235

TABLE 6-10 Values of C and S (Courtesy of Back)
Finishing methods Constants
Points in any 1 in 2 Depth of scraping or
of bearing area surface roughness, mm C t m
3–5 0.39 0.5
20–25
6–8 0.65 0.5
Hand-scraped/ 15–18 1.0–1.3 0.5
hand-scraped
10–12 1.7–2.0 0.5
5–12 2.0–2.6 0.5
Hand-
scraped/ 15–18 1.0R CLA 1.0–1.3 0.5
ground
Peripheral
ground/ 0.5
peripheral 1.0R CLA 0.8–0.9
ground
Finish planning/
finish planning 0.78 0.5
Cast iron joint

Dry condition

Lubricated with
machine oil No. 20
Normal interface pressure
p = 9 kgf/cm 2
1.6
τ, kgf/cm 2 1.2 6.2
0.8
0.4 1.8
0
After maintaining 5-min contact

Shear load τ, kgf/cm 2 1.6 p = 9 kgf/cm 2 time: 24 h.
6.2
1.2
Contact
0.8
1.8
Contact
0.4
0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 time: 5 min.
Displacement d, m m
Figure 6-12 Load-deflection curve at first loading cycle (linear type, by
Kirsanova).