9 Notes on Hydraulic Pump Cooling
9 precautions for hydraulic pump cooling, we’ve sorted out the following 9 points to pay attention to when it comes to hydraulic pump cooling:
Using oil to cool hydraulic pumps and motors
To cool the hydraulic pump and motor, it is occasionally essential to fill the hydraulic pump and motor with oil. However, keep in mind that if the oil pressure in the casing is too high, it may damage the hydraulic pump and motor shaft seal, and for some plunger pumps, the resistance of the oil suction cavity plunger to extend outward will be increased.
The oil circuit in the hydraulic pump is forced to circulate and cool
When the hydraulic pump is frequently operated at zero eccentricity or when the system operating pressure is less than 8 MPa, the hydraulic pump’s leakage is insufficient, the pump body is hot, and the oil circuit can be used for forced circulation cooling.
The hydraulic pump’s built-in relief valve cannot be utilized to regulate the system pressure.
The hydraulic pump’s built-in safety valve can only be utilized as a safety valve and cannot be used to manage system pressure. A basic direct acting safeguard is included into some hydraulic pumps. The valve is only appropriate for use as a safety valve due to its small diameter. Not suited for regulating system pressure. The structure of safety and relief valves is identical, but the two valves are different in size and are employed for various purposes. It is primarily used to stabilize system pressure and control flow as a safety valve for system pressure regulation. Safety valves, on the other hand, are primarily employed to prevent excessive system pressure.The pipe diameter and flow rate are tiny under normal conditions, and the system pressure cannot be restored. As a result, the hydraulic pump’s built-in safety valve has no effect on system pressure regulation.
Large radial forces on the hydraulic pump drive bearing should be avoided.
Avoid putting a lot of radial force on the drive bearing of the hydraulic pump. The drive shaft of most hydraulic pumps cannot withstand additional radial force, in addition to the large radial force that the particularly built hydraulic pump can withstand. If the radial force exceeds the standard, the hydraulic pump’s important parts will be destroyed, or the sealing volume in the pump will not form normally, causing the hydraulic pump to fail sooner.
Avoid relying solely on the constant power speed control circuit.
The constant power speed control circuit should not be utilized alone; instead, the quantitative pump and variable motor comprise the constant power speed control circuit. In general, a higher speed stiffness is required in the speed control loop. The square of the motor displacement determines the speed stiffness of this circuit. Because the speed rigidity of the variable motor drops quickly as the displacement of the variable motor lowers, the torque that can be output correspondingly falls, this circuit is rarely utilized alone.
Avoid mixing pumps and motors
Avoid mixing pumps and motors ，Pumps must be employed as motors if they are to be used in this fashion. In some hydraulic systems, the same component (pump or motor) must perform both pumping and motoring duties at separate periods. Keep in mind that, while a hydraulic motor can theoretically be utilized as a pump, a pump is a conditional motor. Some gear pumps, for example, can only rotate in one direction when used as a motor, whereas hydraulic pumps that distribute oil through a one-way valve cannot be utilized as a motor at all.
Prevent line pressure from decreasing
The outlet of the constant power variable pump is connected to the hydraulic cylinder through a one-way valve and a reversing valve, and the return oil of the hydraulic cylinder must also pass through the corresponding valve flow. to the fuel tank, to prevent the output flow of the constant power variable pump from not reaching the expected demand due to a reduction in pipeline pressure. If some valves are too small and the resulting pressure is too low, the hydraulic pump’s output flow will be too low, failing to meet the hydraulic cylinder’s demand to work swiftly.
The hydraulic pump’s maximum pressure and flow should be chosen with care.
When multiple executive organizations choose to save speed, prevent the selection of only one hydraulic pump When there are multiple executive organizations in the oil supply system, each organization cannot always maintain the coordination of flow and pressure requirements. However, the choice of saving speed control loop inevitably has overflow loss and saving loss. At this moment, if only one pump is used to supply oil, the pump must be selected based on the highest pressure and flow required by the system, which cannot be well adapted to the conditions of low pressure, small flow and high pressure and large flow, resulting in low system efficiency.
Pressure selection of booster tank
Because of the hydraulic system’s requirements, the pressurized oil tank is chosen. Its pressure is P0.16 -0.2MPa.