Consider a 55-cm-long journal bearing that is lubricated with oil whose viscosity is 0.1 k g / m ⋅ s at 20 ° C at the beginning of operation and 0.008 k g / m ⋅ s at the anticipated steady operating temperature of 80 ° C . The diameter of the shaft is 8 cm, and the average gap between the shaft and the journal is 0.08 cm. Determine the torque needed to overcome the bearing friction initially and during steady operation when the shaft is rotated at 1500 rpm.
Consider a 55-cm-long journal bearing that is lubricated with oil whose viscosity is 0.1 k g / m ⋅ s at 20 ° C at the beginning of operation and 0.008 k g / m ⋅ s at the anticipated steady operating temperature of 80 ° C . The diameter of the shaft is 8 cm, and the average gap between the shaft and the journal is 0.08 cm. Determine the torque needed to overcome the bearing friction initially and during steady operation when the shaft is rotated at 1500 rpm.
Solution Summary: The author explains the torque required during the initial operation and the steady state operation of the shaft.
Consider a 55-cm-long journal bearing that is lubricated with oil whose viscosity is
0.1
k
g
/
m
⋅
s
at
20
°
C
at the beginning of operation and
0.008
k
g
/
m
⋅
s
at the anticipated steady operating temperature of
80
°
C
. The diameter of the shaft is 8 cm, and the average gap between the shaft and the journal is 0.08 cm. Determine the torque needed to overcome the bearing friction initially and during steady operation when the shaft is rotated at 1500 rpm.
A frustum-shaped body is rotating at a constant angular speed of 200 rad/s in a container filled with SAE 10W oil at 20°C (? = 0.100 Pa⋅s), as shown in Fig. If the thickness of the oil film on all sides is 1.2 mm, determine the power required to maintain this motion. Also determine the reduction in the required power input when the oil temperature rises to 80°C (? = 0.0078 Pa⋅s).
The space between the shaft and sleeve is filled with an oil of viscosity 6.5 stokes and density 900 kg/m3. The diameter of the shaft is 45 cm and rotates at the speed of 180 RPM. Determine the thickness of oil film between shaft and sleeve and power lost in bearing if the torque transmitted is 80 N-m and length of the sleeve is 100 mm.
A thin plate travels between two plane, parallel, horizontal and stationary surfaces at a constant speed of 7 m/s. The two stationary surfaces are spaced 6 cm apart, and the middle is filled with oil of viscosity of 0.9 Ns/m2.The moving plate submerged in oil has a length of 2 m and a width of 0.5 m.
(i) If the plate moves through the mid-plane between the surfaces, determine the force required to maintain this motion.
(ii) Determine the force if the plate was 1 cm from the bottom surface and 2 cm from the top surface?
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BEARINGS BASICS and Bearing Life for Mechanical Design in 10 Minutes!; Author: Less Boring Lectures;https://www.youtube.com/watch?v=aU4CVZo3wgk;License: Standard Youtube License