Frequent Occurrences of Bushing Seizure and Journal Bearing Failures: Multiple Factors Highlight the Importance of Lubrication System Maintenance

Recently, multiple cases of major engine failures have once again brought the issue of "bushing seizure and journal bearing failures" into the industry spotlight. This severe malfunction often leads to the destruction of core engine components, resulting in substantial repair costs and overall machine downtime. In-depth analysis indicates that this failure is not caused by a single factor but rather stems from a combination of issues related to the lubrication system, assembly techniques, and operational maintenance.

I. Lubrication System Failure: The Primary Culprit
Inadequate lubrication is a high-frequency factor triggering failures. When lubricant supply is insufficient, the friction surface between the bushings and the crankshaft journal loses effective protection, leading to a sharp increase in wear rate. If lubrication passages become blocked due to impurity accumulation, preventing lubricant from reaching critical points, the lubrication balance is directly disrupted. Notably, the intrusion of water or fuel into the lubricant, or the use of inferior and impurity-laden products, significantly reduces lubrication performance, creating hidden risks for bushing seizure and journal bearing failures.

II. Abnormal Oil Pressure Disrupts Lubrication Balance
When oil pressure is too low, the lubrication system becomes like "a kite with a broken string," unable to deliver lubricant accurately to key components such as bushings. This "supply interruption" makes it difficult to maintain the oil film between the bushings and the crankshaft journal, causing a sudden increase in the friction coefficient. Prolonged operation under such conditions easily triggers bushing seizure and journal bearing failures.

III. Assembly Precision Deviations Conceal Risks
Minor errors during assembly can trigger a chain reaction. If the contact area between the bearing and the journal is too small, the force per unit area multiplies, directly tearing the oil film. Similarly, assembly clearances that are "too loose" or "too tight" are equally dangerous—excessive clearance causes rapid lubricant loss, while insufficient clearance exacerbates friction-induced heat. Both scenarios disrupt oil film stability and ultimately induce failures.

IV. Component Defects Cannot Be Ignored
Quality issues with the crankshaft and bushings are potential triggers for failures. Wear of the crankshaft thrust plate can cause excessive axial displacement of the crankshaft, disrupting oil flow paths. Loose contact between the back of the bushings and the seat hole can compromise lubrication stability. Incorrect installation of the main bearing upper and lower plates leading to oil passage blockages, as well as insufficient surface smoothness of the crankshaft and bushings, directly weaken lubrication effectiveness.

V. Improper Operations Accelerate Failures
Operating the engine at high speed and full load before sufficient lubrication is achieved after startup, or subjecting it to long-term overloading, can cause abnormal temperature rises. Prolonged low-speed, high-toroperation under severe overload conditions, coupled with insufficient oil supply, generates localized high temperatures between the bushings and the journal, ultimately leading to seizure failures.

VI. Other Hidden Factors Require Comprehensive Prevention
The use of inferior air filters allows large amounts of particulate matter to enter the engine, causing abrasive wear. Coolant leakage into the oil system leads to oil emulsification, degradation, and loss of viscosity, preventing the formation of an effective oil film. Damaged gaskets or gaps at the suction coil connection point can allow the oil pump to suck in air, resulting in oil supply interruption. These hidden issues can also trigger bushing seizure and journal bearing failures.

Mingyue Bushings Reminder: Preventing bushing seizure and journal bearing failures requires systematic measures. Regularly inspect the lubrication system to ensure oil quality and unobstructed passages. Strictly standardize assembly processes to guarantee proper clearances and installation accuracy. Avoid improper operations such as overloading. Use high-quality filtration systems to prevent the entry of external contaminants. Only through comprehensive management and standardized operations can this catastrophic failure be effectively prevented, ensuring long-term stable equipment operation.