Effect of Oil Evacuation on the Static and Dynamic Properties of Tilting Pad Journal Bearings

Abstract

An experimental study has been conducted to determine the effects of oil evacuation from the bearing cavity on the steady-state and dynamic operating characteristics of tilting pad journal (TPJ) bearings. The tests were carried out on five pad TPJ bearings with a diameter of 98.6 mm (3.8815 in), an L/d ratio of 0.4, and a preload of 0.3. The shaft rotational speed ranged from 3000 to 15,000 rpm. Evacuation of the oil from the bearing cavity was achieved by enlarging the clearance of the bearing end seals.

Steady state performance evaluation has been based on a comparison of the following operating parameters:

•	relative bearing and shaft displacement
•	bearing operating temperature, and
•	power loss.

Bearing operating temperatures and power loss have been significantly reduced as a result of oil evacuation. It has also been found that a reduction in the oil flow led to a lower power loss, most likely as a result of reduced churning loss. It has also been concluded that at a lower oil flow, oil evacuation led to a reduction in bearing stiffness and damping coefficients. With the highest bearing load, these reductions ranged from 20 to 30%.

Review led by Gordon Kirk

KEY WORDS:

• Fluid-Film Bearings
• Tilting Pad Bearings
• Bearing Dynamics

Notes

Review led by Gordon Kirk