Selection and Calculation of Bonfiglioli RAN Right Angle Gearbox

The calculated radial load must be less than the corresponding rated radial bearing capacity [R ₙ₁] (input shaft) and [R ₙ₂] (output shaft) in the performance table:

Rc one≤Rn one and

Rc two≤Rn two 

R c1≤R n1 And Rc2≤R n2

3.2 Axial Load [A] Verification

For applications that require axial thrust, such as screw conveyors and lifting screws, the RAN series provides clear guidance on axial bearing capacity.

General principle:

When the axial load and the rated radial load act simultaneously, the allowable axial load is about 20% of the radial bearing capacity.

If there is no radial load on the shaft, the maximum allowable axial load can reach 50% of the rated radial bearing capacity.

RAN 1/RAN 2/RAN 2R Special Axial Heavy Duty Series:

These three products are designed specifically for applications that primarily involve axial loads, such as ball screw lifting systems. The bearing system has been strengthened for axial force, and under the condition of input speed n ₁ ≤ 100 min ⁻¹, the allowable axial loads are:

RAN 1：50,000 N

RAN 2：80,000 N

RAN 2R：150,000 N

When the input speed exceeds 100 min ⁻¹, it is necessary to consult Bonfiglioli's technical department for accurate calculation of bearing life.

3.3 Peak torque verification

The instantaneous peak torque (impact load) that the gearbox is allowed to withstand should not exceed 200% of the rated torque. If there are frequent impact loads in the application, it is recommended to add hydraulic couplings, friction clutches, or torque limiters in the transmission chain to protect the gearbox from damage.

Lubrication Strategy: The Key to Long Life Operation

There are significant differences in lubrication methods for different machine base numbers in the RAN series, and engineers need to choose the correct maintenance strategy based on the product model.

4.1 "Lifetime lubrication" model (maintenance free)

Suitable for RAN 8, 15, 18.14, 20, 20CAVO, 25:

Lubricating medium: synthetic grease (GADUS S5 V142W 00)

Maintenance requirement: Under normal operating conditions without pollution, there is no need to regularly replace lubricating grease, and the product is maintenance free within its expected service life.

4.2 "Lifetime oil bath lubrication" model

Suitable for RAN 24, RAN 1, RAN 2, RAN 2R:

Lubricating medium: Synthetic oil (OMALA S4 WE 320)

Special design: RAN 1/2/2R is equipped with an oil level observation window, which facilitates visual inspection of the oil level, but does not require oil change under normal operating conditions.

4.3 Models that require on-site lubrication

Applicable to RAN 28, 38, 48:

Factory condition: Does not contain lubricating oil, customers need to add it themselves before installation.

Recommended oil: OMALA S4 WE 320

Oil quantity reference (B3 installation position):

RAN 28：1.7 L

RAN 38：3.0 L

RAN 48：4.5 L

Important reminder: Different installation positions (B6, B7, etc.) require different amounts of oil, and the installation orientation must be clearly marked when ordering to provide Bonfiglioli with correct oil level guidance.

4.4 Suggestions for Oil Change Interval

For gearboxes that are not "lifetime lubricated" and require regular oil changes, Bonfiglioli recommends determining the oil change interval based on the oil temperature:

Oil temperature [° C] Mineral oil change cycle [h] Synthetic oil change cycle [h]

< 65 8,000 25,000

65 - 80 4,000 15,000

80 - 95 2,000 12,500

Safety warning: Regardless of the lubrication method, when the ambient temperature is below -10 ° C, the gearbox must be gradually and uniformly preheated before starting, or run without load until the internal temperature rises above -10 ° C before loading, otherwise it may cause lubricant viscosity to be too high and lead to lubrication failure.

Installation and Storage Engineering Specification

5.1 Key points of installation

Fit tolerance: The inner hole of the transmission component installed on the output shaft must comply with ISO H7 tolerance to avoid interference fit and damage to the bearing or gear.

Anti corrosion treatment: Before installation, all mating surfaces should be cleaned and coated with anti rust protective agent.

Outdoor installation: Rain cover and sun shading device should be equipped to avoid direct exposure of the gearbox to rainwater and strong solar radiation.

5.2 Long term storage specifications

If the gearbox needs to be stored for more than 6 months:

Rust prevention treatment: All exposed machined surfaces (flange faces, shaft extensions, couplings, etc.) must be coated with Mobilarma 248 or equivalent rust inhibitor.

Moisture proof placement: The gearbox should be placed on a wooden pallet and direct contact with the ground is strictly prohibited.

Oil seal protection: Place the gearbox with the oil drain plug facing upwards and completely fill it with lubricating oil to prevent the seals from drying out. Before reactivation, drain to the correct oil level.

Selection checklist

After completing the selection and system design, it is recommended that engineers check the following items one by one:

Is the calculated torque [M ꜀₂] less than or equal to the rated torque [M ₙ₂] in the performance table?