Multistage centrifugal pump pump shaft fracture is one of the most serious failures of multistage pump, the consequence is to directly make the multistage centrifugal pump can not be used, which is the most common cause of the pump shaft bearing, then what is the cause of the damage of the multistage pump shaft bearing? After the long-term summary of Changsha Zhonglian pump technical engineers, there are the following nine common reasons for the damage of multistage centrifugal pump shaft bearing, understand the causes of bearing damage, you roughly know the causes and solutions for the fracture of the multistage centrifugal pump shaft, then let's take a look。
1、Unreasonable design:
1.1Insufficient design strength: The pump shaft may not be designed with sufficient consideration for its required load capacity, resulting in the actual operation of the work requirements.
1.2Improper material selection: Improper material selection of impeller and shaft, such as too high hardness or insufficient strength, may lead to fatigue fracture.
1.3Too high speed: too high speed will cause the liquid flow rate in the pump too fast, the impeller is subject to large impact force, easy to break.
2、Manufacturing quality issues:
2.1Unqualified material: The pump shaft manufacturing material may have defects, such as impurities, bubbles, etc., which will reduce its strength.
2.2Machining errors: Machining errors in the manufacturing process can result in the size or shape of the pump shaft not meeting the requirements, which can affect its performance and life.
3、Operation and maintenance issues:
3.1Long-term overload operation: multi-stage centrifugal pump working in the overload state for a long time will cause the bearing to be subjected to large torque, thereby increasing the risk of shaft breakage.
3.2Bearing damage: Bearing damage will lead to uneven bearing force, which will lead to shaft breakage.
3.3Poor lubrication: Poor lubrication of the pump shaft will lead to increased friction, generate heat, and accelerate the wear and fracture of the shaft.
Installation and commissioning problems:
4、Improper installation: there may be improper installation during the installation of the pump, such as misalignment of the axis, improper adjustment of the bearing clearance, etc. These problems will affect the normal operation of the pump shaft.
Inadequate debugging: Before the pump is put into operation, if insufficient debugging or improper debugging parameters are set, it may also cause the pump shaft to break during operation.
5、Other reasons:
5.1Foreign matter stuck: Foreign matter entering the pump may cause the rotor to bite or stick, resulting in the fracture of the pump shaft.
5.2Check valve failure: In the sudden stop of the pump, if the check valve fails, it may make the pump suddenly reverse under the action of the water hammer, resulting in the fracture of the pump shaft.