What are the common causes of leakage in the ZQD400-180 gear reducer housing

1、 Sealing system failure

Self aging/incorrect selection of seals: During long-term operation, oil seals and gaskets are subjected to high temperatures and oil corrosion, resulting in hardening, cracking, and lip wear; Misuse of ordinary nitrile rubber parts that are not heat-resistant, instead of fluororubber materials that are suitable for working conditions, accelerates seal failure and causes leakage.

Auxiliary sealing structure failure: The breathing valve is blocked by oil and dust, and the pressure cannot be released after the box is heated up, causing the oil to be "pressed out" of the weak seal; The sealing ring of the oil window is aging and cracking, and oil is leaking out from the observation window position.

2、 Insufficient assembly and installation accuracy

Improper assembly of components: oil seal press fit skewed, lip scratched by shaft shoulder, unable to tightly fit the shaft surface; There are residual old adhesive and oil stains on the joint surface of the box, uneven application of sealant resulting in fractures, bolts not tightened in diagonal order, and uneven stress on the joint surface forming gaps.

Overall installation deviation: Insufficient alignment accuracy between the reducer, motor, and working machine, unstable base fixation, severe vibration during operation, resulting in gradual loosening of end caps and box bolts, exacerbating seal wear, and oil leakage from gaps.

3、 Improper lubrication management

Oil level and oil out of control: When the fuel level exceeds the upper limit of the oil gauge, the oil is violently stirred during gear operation, and a large amount accumulates at the shaft seal and joint surface and overflows; Choose lubricating oil with low viscosity, as the oil is prone to penetrate through the sealing gap; Deterioration of oil products mixed with water and impurities can corrode seals and increase the risk of leakage.

Poor oil return channel: The design of the oil return groove in the box is unreasonable or blocked by impurities, and the accumulated oil at the oil seal cannot flow back in time, forming a local high-pressure zone that squeezes the oil out of the sealing gap.

4、 Manufacturing and equipment aging defects

Hidden dangers in casting processing: There are defects such as sand holes, air holes, cracks, etc. during the casting of the box body, or insufficient machining accuracy and poor flatness of the joint surface. After long-term operation, oil slowly leaks from micro holes and machining gaps.

Core component wear and deformation: scratches and grooves appear on the journal due to long-term friction, which damages the flatness of the sealing surface; The box body undergoes slight deformation due to long-term heavy load and temperature difference changes, and the joint surface is not tightly adhered, forming an oil leakage channel; After bearing wear, the clearance increases, driving the shaft to rotate eccentrically, further damaging the sealing environment.

5、 Abnormal operating conditions

High temperature and temperature difference impact: Long term overload operation can cause gear friction to generate ultra-high temperatures, resulting in a significant decrease in lubricating oil viscosity and easy penetration, while accelerating seal aging; Frequent temperature fluctuations, asynchronous thermal expansion and contraction of metal components and seals, repeated loosening of bolts, and insufficient clamping force on the sealing surface can cause leakage.

Corrosion in harsh environments: Dust and corrosive media enter the sealed parts, wear and corrode the seals, damage the sealing structure, and ultimately lead to oil leakage.