Lubricant delivered from the oil pump makes umbrella valve in the BFD distributor drive upwards.
When the umbrella valve closes central hole of the core bar, the piston overcomes the spring force to rise. Lubricant stored in the oil cavity is drained out.
When piston moves to the top point of oil cavity, oil draining is completed.
When oil pump stops oil supplying, the pressure release valve is automatically released to make lubricant in the main oil pipe to reset through the decompression valve. At this moment, the system pressure is reduced, and piston in the distributor starts reciprocating with the function of spring. When the umbrella valve resets and closes oil outlet of the distributor, the piston delivers lubricant in the lower cavity through the core bar, and oil supply for the next time is ready.
