Problems with the oil station for steel rod coal grinding machines!

Just talking nonsense – high-pressure oil is used to lift the bearings during startup and shutdown; one purpose is to prevent the bearings from locking up, and the other is to reduce the load on the motor during startup. Not used when driving or parking. Low-pressure oil is used to lubricate the bearings, and it must be supplied continuously unless the machine is stopped.

What is the purpose of the high-pressure fuel pump starting up when the vehicle is parked? When the mill is stopped, the oil supplied by the low-pressure oil pump isn’t used up in an instant; its oil film isn’t exhausted that easily, right? Also, how do the high-pressure and low-pressure oil pumps function when the mill is shut down? I can’t figure this out; could someone with more knowledge please explain it?

When stopping, either start the high-pressure oil pump manually first – the high-pressure oil then supports the cylinder body instead of the oil film disappearing – or use the stop button to trigger the automatic start of the high-pressure oil pump; this is necessary in order to disengage the starting clutch and stop the main motor under no-load conditions

Before starting the mill, the low-pressure oil pump is activated first, followed by the high-pressure oil pump, which lifts the bushings and reduces the starting power required for the mill; in practice, this process is controlled via programming. What we see are three low-pressure oil pumps, with two in operation and one as a backup, and two high-pressure oil pumps, with one in operation and one as a backup.

There are usually 2 high-pressure oil pumps, which start simultaneously during startup and shutdown; one pump is assigned to each bearing. Large rotating equipment, such as large air compressors and turbines, generally requires high-pressure oil pumps; the purpose of this is to lift the main shaft at low speeds, thereby reducing friction between the shaft and the bearing shells. At present, it is not possible to ensure that the high-pressure oil pump starts in time to supply oil in the event of a sudden shutdown of the host machine. However, I don’t think it’s a big deal; the coal grinder operates at a low speed, so it will stop quickly when it comes to a halt suddenly. Moreover, the low-pressure oil pump is still working, so there’s no significant impact.

The discussion went well; the weight of the mill body together with the steel rods exceeds 100 tons. Sliding bearings are generally used for the shaft bushings; during startup, an oil pressure of 12 MPa is applied to create a thin layer of oil film between the shaft and the bushings. After starting the rotation, use this rotation to create a wedge-shaped oil film with the low-pressure oil; at this point, the high-pressure oil pump can be stopped. When shutting down, the high-pressure oil pump also needs to be turned on first. In short, there is only one goal: to ensure that the shaft and the bearing shells remain in liquid contact throughout the processes of startup, operation, and shutdown. Theoretically, such bearing shells will never wear out or get damaged! The source of high-pressure oil is introduced from the low-pressure oil outlet, that is, in series! These are all common knowledge in mechanics!

In my opinion, the rotational speed and the load borne by the bearings (which can also be understood as the stress) affect the distribution of the oil film; this is why splash lubrication is used in some places while pressure lubrication is used in others

The shape of the mill shaft bearings does not fit perfectly with the shaft; there is a slight \"V\"-shaped indentation. As for shutting down the machine, my opinion is that high-pressure oil plays a role in preventing this situation – unlike during startup, it stops the force from being distributed evenly across the bearings and instead causing it to concentrate in certain areas, thus avoiding mechanical damage

The low-pressure oil pump is used when the mill is rotating; it can be found in various high-speed rotating devices, and it operates on the principle of dynamic pressure lubrication. The high-pressure oil pump needs to be started when the mill is started or stopped. High-pressure oil pumps are also used during mill maintenance, using oil pressure to lift the shaft in order to prevent damage to the shaft and bearings.