5 tips for optimizing the structure of the gearbox to prevent oil leakage or spillage, and cure stubborn problems
The occurrence of oil leakage or oil spillage in the gearbox is often related to the unreasonable design of the internal structure of the casing, poor oil return, and a single sealing method. By targeted optimization of the box and related structures, this problem can be effectively solved from the source. Here are several key tips for optimizing box structure:
1. Add and optimize the design of oil guide/return groove
Lubricating oil is prone to splashing and accumulating during high-speed operation of gears and bearings, leading to increased pressure and leakage. When designing the box structure, it is necessary to ensure "smooth flow". A return oil groove inclined towards the inside of the machine can be opened at the center of the lower tile of the bearing seat (it is recommended to use a 15 °~30 ° inclined groove), and a gap can be opened directly opposite the return oil groove at the straight mouth of the end cover. This can guide the excess lubricating oil thrown out to flow smoothly back to the oil pool in a certain direction, avoiding a large accumulation at the shaft seal. In addition, an oil guide groove with a width of about 5mm and gradually increasing in depth can be opened at the bearing position of the housing, slightly exceeding the outer side of the bearing to reduce the pressure difference at the sealing point.
2. Improve the structural coordination between the oil blocking ring and the oil slinger ring
The traditional cup shaped oil blocking ring is prone to oil accumulation at the bottom and poor oil return. It is recommended to replace it with a conical oil blocking ring. Using centrifugal force to make the oil spiral back along the conical surface can achieve secondary lubrication and leakage prevention. At the same time, a combination of oil blocking ring and oil slinging ring can be used: an oil blocking ring is installed on the outside of the bearing to block the oil in the clearance between the ball bearings, and a static fitting shaft oil slinging ring (with an outer diameter about 1mm smaller than the end cap) is installed on the outside to block oil leakage on the shaft surface. For high-speed shafts, adding an oil slinger can also prevent the high-temperature lubricating oil mixed with foreign objects from directly hitting the oil seal lip during gear swing, providing excellent protection.
3. Optimize the structure of the inspection hole cover plate and breathable cap
The common cause of oil leakage is the increase in pressure caused by friction heating inside the box. The originally thin inspection hole cover plate can be replaced with a steel plate with a thickness of ≥ 6mm (or even 8mm or more) to prevent deformation after tightening the bolts and uneven joint surfaces. At the same time, make an oil cup style breathable cap and increase the diameter of the breathable hole (if set to 6mm) to prevent it from being easily blocked by dust and oil stains, thereby achieving pressure balance inside and outside the machine. You can also move the position of the ventilation hole above the low-speed shaft to create a labyrinth structure specifically designed to drain oil mist, avoiding oil leakage caused by high oil levels.
