Bonfiglioli 300M planetary gearbox selection and thermal verification guide

P_T = P_TB × f_out × f_Tamb × f_speed × f_pos × f_input × f_air × f_id × f_nb

The key correction factor is:

F_out: depends on the output configuration type (FP/FZ/HC, etc., usually 0.4~0.9, while PC/PZ is 1.0)

F_Tamb: Correction factor at ambient temperature of 40 ° C (usually 0.6~0.75)

F_speed: Correction for input speed different from 1500 min ⁻¹

F_pos: Correction of vertical installation positions (T, O, Q, V) (usually 0.65~0.93)

F_air: Correction for installation in confined spaces (wind speed ≤ 1.4 m/s) (usually 0.5~0.75)

F_id: Correction of intermittent working system (the lower the intermittent rate, the higher the correction coefficient, up to 2.0)

Judgment condition: P_T ≥ P_ {r1} (required input power). If P_T<P_ {r1}, an auxiliary cooling system must be selected.

3. Auxiliary cooling system

When the thermal power is insufficient, the 300M series can be equipped with the following cooling solutions:

FAN (forced ventilation): Install a cooling fan on the input shaft (suitable for input speed ≥ 900 min ⁻¹)

SR (Cooling Coil): Install water-cooled coils in the oil tank (AB3 installation position only)

MCRW (water oil cooling unit) or MCRA (air oil cooling unit): an independent cooling unit that provides cooling power ranging from 3.5 kW to 19.6 kW

MOP (forced lubrication pump set): Especially suitable for AB6 installation position, ensuring forced lubrication of the upper bearing

Radial/axial load verification

The external transmission components on the output shaft (sprockets, pulleys, gears, etc.) will generate radial forces (R_c) and axial forces (A_n), which must be within the verification range.

1. Radial load calculation

Actual radial load calculation formula:

R_{c1-2} = (2 × T_{r1-2} × K_r) / d

Among them, Kr is the transmission type coefficient:

Chain drive: Kr=1

Gear transmission: Kr=1.25

V-belt drive: Kr=1.5~2.5

2. Correction of load application point

The manual provides allowable radial load values for each machine base under different load point distances (x, distance from the shaft shoulder). The actual load must meet the following requirements:

R_{c2} ≤ R_{x2} × fh₂

Where fh ₂ is the load correction factor corresponding to the life factor (the higher the life requirement, the smaller the allowable load).

3. Axial load (thrust)

The allowable axial thrust is: A_ {c2} ≤ A_ {n2} × fh ₂. When axial force and radial force act simultaneously, it is necessary to refer to the Axial/Radial load relationship curve in the manual for joint verification.

4. Special verification of VK output configuration

For the VK configuration (mixer specific output), it is necessary to determine the allowable radial load based on the position of the load application point x and the ratio of axial force to radial force (A_n ₂/R_n ₂), by checking the dedicated curve graph, and verifying it with the velocity correction factor f_n ₂ and the life correction factor f_L.

Special considerations for FP hollow shaft configuration

For shaft mounted gearboxes using shrink disc installation (FP configuration), the installation method will generate additional reaction forces, affecting the bearing life and output shaft strength. Manual requirements:

A torque arm must be used to withstand the reverse torque of the gearbox.

The manual provides the minimum length of the reaction arm (L ₁ and L ₂) for each machine base to ensure rated performance is achieved.

For large-sized motors or single-stage gearboxes (especially sizes 300 to 307), it is strongly recommended to consult Bonfiglioli's technical service department for specialized verification.

Installation and lubrication points

1. Installation rules

The installation surface must provide sufficient rigidity, and the mating surface should be machined flat.

For flange installation of spline hollow shaft (FZ), the specified bolts must be used and tightened to the specified torque (the tightening torque of the shrink disc screws is marked with a wrench symbol in the manual).

Before painting, the shaft seal must be shielded and protected to prevent solvents from contacting the seal and causing it to harden and fail.

Before wiring the motor, it is necessary to confirm the rotation direction of the input/output shaft (such as RA/RO options).

2. Lubricating oil selection

The manual provides a chart for selecting the optimal viscosity based on Shell lubricants, selecting the appropriate viscosity according to the ambient temperature and output speed (ISO VG 150, 220, 320, 460, etc.).

Synthetic oil (PAG): Shell Omala S4 WE 150/320 is recommended for a wider operating temperature range and longer service life.

Mineral oil: suitable for standard operating conditions, with better economy.

Temperature limit: The minimum operating temperature for synthetic oil can reach -30 ° C, while for mineral oil it is -10 ° C. The maximum allowable oil temperature is+95 ° C.

3. Long term storage

For devices with a storage period exceeding 6 months, SLM (mineral oil compatible) or SLP (polyethylene glycol oil compatible) long-term storage options can be selected. When the gearbox leaves the factory, it is filled with anti-corrosion protective fluid instead of standard lubricating oil to ensure the integrity of internal parts during long-term storage. After storage for more than 2 years, it must be inspected by Bonfiglioli service center before it can be put into use.