Induced Axial Load

Fac = 20kN/(2x1.48) = 6.76kN

Preload vs. Displacement

𝛿𝑎 =0.000077

sin(𝛼)∙𝑄0.9

𝐿𝑤𝑒0.8

𝑄 =𝐹𝑎

𝑍𝑠𝑖𝑛(𝛼)=

4.32

25 ∙ sin(15.287)= 0.655𝑘𝑁

𝛿𝑎 =0.000077

sin(15.287)∙6550.9

150.8= .01146 ≈ 11.5𝜇𝑚

https://koyo.jtekt.co.jp/en/support/calculation-tool/

4323N = 11.3µm

Roller and Raceway Profiles Can Dramatically Change Masta Stiffness

Optimizing PreloadLife with no preload 40kN

10kN

100hrs

25µm

50µm

Optimizing left preload results in 2% improvement but reduces right by 1.5%

Add Temperature

Left

Right

Left

Right

Preload Test

No Temperature

Aluminum Housing α1 = 23.7x10-6 (1/ ⁰C)Steel α2 = 12.5x10-6 (1/ ⁰C)Shaft 60⁰C

∆𝐿𝑇2 = 𝛼2∆𝑇𝐿 = (12.5x10-6)(60-23)(300) = 0.138mm

Housing 60⁰C∆𝐿𝑇1 = 𝛼1∆𝑇𝐿 = (23.7x10-6)(60-23)(300) = 0.263mm∆𝐿𝑇1,2 = 0.125𝑚𝑚

254mm

300mm

Left

Right

0.130mm

130µm

50µm

90µm

180µm

200µm

Optimized preload for life at this condition