1.
Determine the Sommerfeld number considering the following data for hydrodynamic bearing?
1. Diameter of bearing = 120 mm
2. Bearing pressure = 5 N/mm2
3. Oil viscosity = 30 cP
4. Journal speed = 900 rpm
5. Radial clearance = 150 microns
2.
Which of the following formula is used to calculate oil-film thickness in hydrodynamic bearings?
3.
Lubricating oil used in hydrodynamic bearing has total flow rate of 0.340 l/min and side leakage of 0.1520 l/min. If mass density of oil is 600 kg/m3 and specific heat is 1.05 kJ/kg oC, what is the rise in temperature if power lost in friction is 0.05 kW?
4.
Lubricating oil of mass density 800 kg/m3 used in 360o hydrodynamic bearing has a flow rate of 6000 mm3. Neglecting side leakage if temperature rises to 10 oC and specific heat is 1.55 kJ/kg oC, what is the rate of heat dissipated in the bearing?
5.
A journal of 120 mm diameter rotates in a bearing at a speed of 1000 rpm. What is the power lost during friction if 8 kN radial load acts on the journal and coefficient of friction is 2.525 x 10-3?
6.
What does number 6 indicate in the class of wire rope 6 x 37 (18/12/6/1)?
7.
Lang lay ropes offer more resistance to __________
8.
Which of the following statements is/are true for V-belts?
9.
If pressure angle is 22o and coefficient of friction is 0.05. What is the axial force acting on the worm gear designated as 1/40/10/5, if tangential force of 1200 N acts on it?
10.
What is the shortest distance between worm gear and axes of the worm for a worm gear pair designated as 2/40/10/8?