Bonfiglioli AS Series Reducer Installation and Maintenance Guide

Bonfiglioli AS Series Industrial Reducer: A Complete Technical Manual from Installation to Troubleshooting

In the field of industrial transmission, Bonfiglioli's AS Series parallel axis helical gear reducer is known for its high torque density and modular design, and is widely used in harsh working conditions such as metallurgy, lifting, chemical engineering, and material conveying. However, even the most reliable mechanical units can greatly reduce their lifespan and efficiency if there are omissions during installation, commissioning, or maintenance. This article is based on the manufacturer's official technical documentation and combined with frontline service experience to break down the key points of full lifecycle management for AS Series reducers from unboxing to stable operation, helping engineers avoid common pitfalls and solve practical operational pain points.

Key check before installation: the "golden two hours" that cannot be ignored

Before hoisting the heavy gearbox into place, many teams are eager to get started, but often overlook a few fatal details. According to the requirements of Section 4 (INSTALLATION) of the manual, the following steps must be strictly followed:

Triple verification of Nameplate

In addition to confirming that the model is consistent with the order, special attention must be paid to the mounting position code (such as B3, B5, V6, etc., see page 19 of the manual for details). This code determines the position of the Oil Level Plug and Breather Plug, and if installed incorrectly, it will cause the lubrication system to completely fail. At the same time, check the maximum surface temperature on the nameplate, which is the core basis for determining the safety distance of equipment in ATEX explosion-proof environments.

Discharge and flushing of stored oil products

For reducers that have been filled with rust proof oil internally at the factory, if the oil is incompatible with the synthetic oil or mineral oil you plan to use, it must be thoroughly drained and the inner cavity flushed with a special solvent before adding new oil. Warning on page 12 of the manual: Do not allow solvents to come into contact with the seal rings, as this may cause swelling and deformation of the seal lips, leading to early leakage.

Precise fit between output shaft and flange

The AS Series offers two output formats: Solid Shaft and Hollow Shaft with Keyway. On page 20 of the manual, a strict tolerance table is provided: for example, for AS 80 model, the Spigot Diameter tolerance for output shaft positioning is f7 (-0.056 to -0.108 mm), while the fitting tolerance for customer components must be H8 (0 to+0.081 mm). It is strictly prohibited to paint in the sealing area. Only Kluber paste 46 MR 401 and other anti Fretting Corrosion assembly paste should be applied.

Core installation technology analysis: precise docking between hollow shaft and IEC motor

1. The "press fit trap" of hollow output shaft

For AS reducers installed with hollow shafts (commonly seen in conveyor drives), the key is the use of tie bolts and spacers. The illustration on page 15 of the manual emphasizes:

The customer must use their own tension bolts to push the reducer into the main shaft of the equipment, and hammering is strictly prohibited to avoid damaging the bearing cage.

The thrust must act on the spacer ring at the hollow shaft end, not on the shaft itself.

During this process, it is necessary to monitor the axial displacement to ensure that the locking torque of the shrink disc (if any) of the hollow shaft meets the specifications.

2. The "anti leakage art" of installing IEC standard flange motors

When installing motors that comply with the IEC 60072-1 standard (see page 16 for details), bolt locking alone is not enough:

Sealing glue strategy: Loctite 510 flat sealing glue must be evenly applied to the adhesive flange surface of the motor and reducer. After the motor is pressed together, Loctite 5366 (or equivalent performance product) should be applied to the gap at the outer edge of the flange. This is not just for oil protection, but also to comply with ATEX 2D/2G explosion-proof requirements and prevent dust or gas from entering the mating surface and generating friction sparks.

Bolt torque management: The torque table (Tab 1) on page 14 of the manual clearly states that for AS Series aluminum enclosures, it is strictly prohibited to use bolts higher than grade 8.8, otherwise it will cause the threads of the enclosure to slip. For example, M12 bolts have a torque of 87.3 Nm for 8.8 grade and 127 Nm for 10.9 grade, with the latter's high preload force sufficient to crush aluminum flanges.

Lubrication management system: the 'blood' that determines the lifespan of the gearbox

AS Series allows the use of mineral oil, PAO synthetic oil, or PAG polyethylene glycol oil. But on page 17, it is emphasized that once synthetic oil is selected, the first oil change (break in period oil change) must be carried out after the first 500 hours of operation, and the subsequent oil change cycle depends on the oil temperature: