Bonfiglioli Precision Planetary Gearbox Selection and Application Guide

Bonfiglioli Precision Planetary Gearbox Selection and Application Guide

Introduction: The Value of Precision Planetary Gearboxes in Industrial Transmission

In the field of industrial automation and robotics, the accuracy, rigidity, and dynamic response of the transmission system directly affect the overall performance of the machine. Bonfiglioli, with nearly 20 years of experience in motion control, has developed a full range of precision planetary gearboxes covering high dynamic servo to economical positioning. Its product line is divided into two major camps: Performance Line - targeting high-end applications with high torque density, extremely low backlash, and high stiffness requirements; Effective Line - meets medium precision requirements with high cost-effectiveness, flexible installation, and good compatibility. Whether it is packaging, material handling, automatic warehousing, or machine tool feeding, correct selection and configuration are the key to unleashing the potential of equipment. This article is based on the official technical manual of Bangfeili, systematically sorting out the characteristics of each series, selection calculation process, and engineering precautions, to help engineers quickly match the optimal solution.

Overview of Product Series Panorama

2.1 Performance Line

This line is designed specifically for high dynamic, high-precision servo applications and includes the following series:

TQ series: direct connection type, output torque up to 1600Nm, backlash ≤ 3arcmin (single-stage), leading torque density, IP65 protection, optional reinforced bearings.

TQK series: Right angle type (bevel gear planetary), saving installation space, back clearance ≤ 4arcmin (two-stage), suitable for compact layout.

TQF series: with output flange, standardized interface, easy to install quickly, high tilt torque bearing capacity.

TR series: Modular design, providing multiple versions such as coaxial, right angle input, and right angle output, multi-stage transmission, wide speed ratio range (3~729), and bearing life of 20000 hours.

MP series: Similar to TR but with slightly larger backlash (standard ≤ 15 arcmin), better cost-effectiveness, suitable for medium precision requirements.

2.2 Effective Line

For cost sensitive applications with moderate precision requirements:

TQFE/TQFEK: Direct connection and right angle type, compact flange structure, IP54， Back clearance ≤ 10arcmin (single-stage), economical type.

SL series: specially optimized for synchronous belt transmission, with output end designed with adaptive pulleys, high radial load capacity, and ultra compact.

LC/LCK: Direct connection and right angle type, outstanding cost-effectiveness, standard backlash ≤ 12arcmin, P option can increase torque.

MPE/MPEK: Medium precision positioning, high flexibility, multiple shaft end configurations.

KR series: bevel gear spiral gear, compact size, backlash ≤ 8arcmin, optional hollow shaft/solid shaft, IP65， Support S1/S5 working system.

Selection of core calculation steps

The correct selection should be based on the torque, speed, load, and lifespan requirements of the actual working conditions. The following is the key calculation process (refer to pages 14-20 of the manual):

3.1 Determine the transmission ratio and output speed

From the required output speed n ₂ and the rated motor speed n ₁:

i=nonentwo

i= n two n one 

If the operating condition includes multiple speed ranges, the equivalent output speed n ₂ _SQ needs to be calculated:

n two EQ=ntwo(one)tone+ntwo(two)ttwo+⋯+ntwo(n)tntone+ttwo+⋯+tn

n 2EQ= t one+t two+⋯+t n n 2(1)t one+n 2(2)t two+⋯+n 2(n)t n 

3.2 Calculate equivalent output torque (considering variable load)

For multi-stage load torques M ₂ (1)... M ₂ (n), their equivalent values are weighted by the cube root:

M two EQ=Mtwo(one)three n two(one)tone+M two(two)three n two(two)t two+…n two(one)tone+n two(two)t two+… three

M 2EQ= three  n 2(1)t one+n 2(2)t two+…M 2(1)three n 2(1)t one+M 2(2) three n 2(2)t two+…  

This formula is applicable to cyclic working conditions with variable speed and variable torque (such as frequent start stop).

3.3 Speed coefficient fn

The speed coefficient reflects the influence of input speed on the load-bearing capacity. Definition

Kn=one thousand

iK n= ione thousand(Experience value), if n two EQ⋅i≥Knn 2EQ⋅i≥K n

If fn=1, otherwise the graph will show fn (less than 1, derating is required).

3.4 Temperature coefficient fT

When the ambient temperature is above 30 ° C, the rating needs to be reduced. The manual provides a correction curve for 30-60 ° C, usually fT ≈ 0.9 at 40 ° C and ≈ 0.8 at 50 ° C.

3.5 Cycle frequency coefficient fz

For frequent start stop or forward/reverse rotation (S5 working system), fz should be calculated based on the number of cycles per hour Z (please contact the manufacturer if Z>6000). When ultimately selecting a gearbox, its rated torque Mn2 must meet the following requirements: