Key Points for Installing a Gearbox

The installation of a gearbox is a delicate and complex task that requires high technical standards. It is crucial to strictly follow the operating procedures and design specifications during the installation process. The general sequence for installation includes: leveling and aligning the equipment, cleaning and assembling, adjusting, and conducting a trial run.

Cleaning the Installation Shaft:

Before installation, the gearbox mounting shaft should be cleaned to ensure that it is free from any damage or contaminants.

If the gearbox is to be installed in a tilted position, make sure that the highest gear shaft bearing receives lubrication from the gearbox’s internal gear oil. Additionally, ensure that the air inside the housing can be expelled from the highest point of the housing.

Cleaning and Preparing the Flange:

When assembling the industrial gearbox with the actuator and the prime mover, ensure that the coupling flange is cleaned and polished.

Check the alignment of the flange connection surfaces for flatness, ensuring they are smooth and even. All the bolts around the flange should be properly matched and tightened.

Balancing of Components:

The components involved in power transmission, such as couplings and sprockets, must be balanced to avoid inducing any radial or axial forces that are not allowed.

Typically, assembly fixtures and internal threads at the shaft ends are used, and the transmission parts are pressed into place using bolts. Failing to do so could result in damage to the internal components of the gearbox.

Rigid Fixing and Alignment:

• The gearbox must be rigidly fixed to a solid, level foundation or vertical frame and properly leveled.
• The prime mover, coupling, gearbox, and actuator must have consistent coaxiality to avoid operational imbalance that could impose additional stresses on the input and output shafts and bearings, leading to damage.
• The coaxiality between two connected shaft extensions should be controlled within a tolerance of φ0.1mm. A gap of 2–8mm should be maintained between the shaft end faces, with the exact value depending on the specific conditions of the connected equipment. This ensures sufficient load transfer capability while preventing axial force from being applied to the gearbox bearings.
• To prevent bending of the main spindle and additional forces on the gearbox bearings, the distance between the gearbox and the working machine should be minimized (within 5–10mm) without affecting normal operation.

Lubrication:

• The oil grade should be selected according to the gearbox manufacturer’s recommendations or equivalent oils. The correct oil level is crucial, and each gearbox will have a label indicating the recommended oil type and quantity.
• The oil sight glass on the side of the gearbox indicates the oil level. When adding oil, the level should reach the middle of the sight glass.

Importance of Correct Oil Filling:

In gearboxes using splash lubrication, especially when the load is close to the thermal power, maintaining the correct oil level is particularly critical. In some cases, adding just 15% more oil can raise the operating temperature by 15-20°C above the normal range. This could reduce the lubrication ability of the oil, leading to severe damage to the gearbox.

If the oil level is below the indicated level, the gears may not be adequately lubricated, and splash lubrication will be ineffective.