Bonfiglioli A-Series Helical Inline Gearbox: Field Review After 18 Months

A German systems integrator specialising in airport material handling installed 186 Bonfiglioli A-Series helical inline gearmotors on a new baggage handling conveyor system at a regional European airport. The installation, commissioned in August 2024, covers 1.2 km of conveyor across check-in, transfer, and reclaim sections. This review summarises 18 months of operational data provided to INDASTRA by the integrator's maintenance team.

Application Context

Airport baggage conveyors represent a demanding duty cycle for gearmotors. Individual units start and stop up to 400 times per day under variable load (empty belt to fully loaded with 32 kg baggage). The indoor environment in checked-baggage areas maintains ambient temperatures of 12–28°C year-round, with condensation risk in early morning when cold aircraft ground equipment is brought inside. The integrator's specification required a gearmotor capable of 10 million start cycles over a 10-year service life without bearing replacement, with noise output below 72 dBA to comply with the terminal's occupational noise limits.

Selected Configuration: Bonfiglioli A Series

The Bonfiglioli A-Series is a range of helical inline (coaxial) gearboxes designed for conveyor and material handling applications. The integrator selected the A 304 and A 305 frame sizes depending on conveyor section loading requirements:

• A 304: 156 units. Output torque up to 360 Nm. Paired with 1.5 kW, 4-pole IE3 Bonfiglioli motor (BN series, B14 flange mount). Used on straight conveyor runs with belt width up to 800 mm.
• A 305: 30 units. Output torque up to 520 Nm. Paired with 2.2 kW, 4-pole IE3 motor. Used on inclined sections (maximum 12° incline) and curved belt sections with additional radial load.

Gear ratio selected: 18.78:1 across all units, giving an output speed of approximately 77 RPM at 50 Hz (1450 RPM motor input). Belt speed: 1.2 m/s for flat sections, 0.9 m/s for inclined sections (achieved via VFD on the inclined units). Output shaft configuration: solid, hollow bore options evaluated but solid chosen for maintenance simplicity.

18-Month Performance Data

Reliability and Maintenance Events

Over the 18-month review period (August 2024 to January 2026), the 186-unit installation recorded zero gearbox failures requiring unit replacement. Three units required maintenance attention:

• Two units showed elevated gearbox housing temperature (detected by the terminal's BMS thermal scanning at 6-month interval check). Root cause: conveyor alignment drift causing side-load on the output shaft above the rated radial force. Corrected by re-aligning the conveyor section; no internal gearbox damage found on inspection.
• One unit had a terminal box cover seal failure due to a cleaning crew's pressure washer being directed at the motor during terminal cleaning. Not a product defect; seal replaced under standard maintenance.

Cumulative downtime attributable to the gearmotor units over 18 months: 4.5 hours total across the 186-unit fleet. This compares favourably with the integrator's previous installation using a competitor's inline helical units, which had 12 replacement events in the same period for a similar-sized installation.

Noise Measurement

Noise was measured at 1 metre distance from the gearbox housing under full load, using a calibrated Class 1 sound level meter (IEC 61672-1). Results across 15 randomly sampled units:

• Minimum recorded: 64 dBA
• Maximum recorded: 71 dBA
• Mean: 68 dBA

All measurements were below the 72 dBA contract specification. Bonfiglioli's published noise data for the A 304 at this ratio is 68 dBA — the field measurements are consistent with the catalogue value. For comparison, the integrator's previous installation using a worm gearmotor at similar loading measured 74–78 dBA; the helical inline design's rolling gear contact versus the worm's sliding contact accounts for the 6–10 dBA reduction.

Energy Consumption

The A-Series helical inline gearboxes were specified at 97% efficiency per stage (two-stage unit: 94.1% overall). Actual power consumption was metered on a 20-unit section over 30 days and compared against the integrator's design model. Measured efficiency: 93.8% — 0.3 percentage points below the catalogue value, within acceptable tolerance and likely attributable to belt tension variation across the measurement period.

Procurement Notes

Lead time for the initial order of 186 units from Bonfiglioli's Italian stock via INDASTRA: 9 working days to the integrator's warehouse in Frankfurt. The order was placed as a single purchase order with a single delivery; Bonfiglioli maintains sub-assembly stock at European distribution points that allows rapid fulfilment of A-Series standard configurations without factory lead time. Spare unit stock of 4 units (approximately 2.2% of fleet) is held on-site by the integrator.

Unit cost delivered to Frankfurt: competitive against equivalent Flender (Siemens) SIMOGEAR units but above SEW's SA series at the same torque rating. The integrator's engineering lead noted that Bonfiglioli's catalogue noise data and the quality of dimensional drawings provided during the design phase were factors in the selection decision alongside price.

INDASTRA supplies Bonfiglioli A-Series gearmotors across the full torque range. Browse the gearbox catalogue for specifications and current availability, or contact our technical team for multi-unit project pricing.