Bonfiglioli VF-W IE2/IE3 Worm Gear Reducer: Energy Efficiency Selection and Application Practice Guide

Bonfiglioli VF-W IE2/IE3 Worm Gear Reducer: Energy Efficiency Selection and Application Practice Guide

Against the backdrop of rising global energy costs and increasingly strict environmental regulations, the energy efficiency of industrial transmission systems has become a core consideration factor in engineering projects. The mandatory requirement for motor energy efficiency in the EU EC 640/2009 regulation marks the transition of high-efficiency motors from "optional" to "mandatory". As a global leader in power transmission and control solutions, Bonfiglioli's VF-W series worm gear reducer combined with IE2/IE3 high-efficiency motors provides industrial users with an ideal solution that balances high performance and low energy consumption.

Understanding energy efficiency levels: IE1, IE2, IE3 and EC 640/2009 regulations

When choosing a motor, the first thing to understand is its energy efficiency rating. The International Electrotechnical Commission (IEC) standard IEC 60034-30-1 defines three energy efficiency levels:

IE1 (Standard Efficiency): Standard Energy Efficiency.

IE2 (High Efficiency): High energy efficiency.

IE3 (Premium Efficiency): Ultra high energy efficiency.

The European Commission Regulation EC 640/2009 mandates a lower energy efficiency limit for motors at the legal level, with the following key time points:

Starting from June 16, 2011, motors must meet the IE2 energy efficiency rating.

Starting from January 1, 2015, motors with a rated power between 7.5 kW and 375 kW must reach IE3 level or be equipped with IE2 motors controlled by a frequency converter.

Starting from January 1, 2017, motors with a rated power between 0.75 kW and 375 kW must reach IE3 level or be equipped with IE2 motors controlled by a frequency converter.

Important exemption: This regulation does not apply to brake motors, motors that are fully integrated into products (such as gearboxes, pumps, fans) and cannot be independently tested, and motors used in potentially explosive environments (ATEX). This means that when selecting motors for non braking and independent use, the above energy efficiency requirements must be strictly followed. Bonfiglioli's BX/BE (IEC motor) and MX/ME (compact motor) series fully cover IE2 and IE3 energy efficiency levels, helping users easily meet compliance requirements.

Efficiency characteristics: dynamic efficiency and static efficiency

Understanding the definition of efficiency is crucial for making the right choices. The Bonfiglioli directory provides two key efficiency parameters:

Dynamic efficiency (η d): It is the ratio of output power to input power of a gearbox during normal operation (after sufficient running in). The rated torque (Mn2) values given in the catalog have taken into account dynamic efficiency. This means that when selecting, you do not need to additionally compensate for the losses caused by dynamic efficiency.

Formula: η d=P2/P1

Application guidance: Dynamic efficiency is the basis for calculating the required motor power under continuous operating conditions. For example, when calculating the required power of the motor (Pr1), this efficiency value should be used.

Static efficiency (η s): refers to the efficiency of the gearbox during startup. For worm gear reducers, this value is particularly critical. It determines the self-locking ability of the gearbox. When the static efficiency is below 40% -50%, the reducer theoretically has a static self-locking function, which means that the load cannot reverse drive the motor. This is crucial for applications that require safe parking such as lifting and hoisting.

Application guidance: For intermittent working systems such as cranes and elevators, static efficiency must be considered to ensure that the motor has sufficient starting torque.

Practical Selection of VF-W Series and IE2/IE3 Motors

The correct selection is a prerequisite for ensuring system efficiency, lifespan, and safety. The selection process is a systematic engineering that comprehensively considers load characteristics, working hours, energy efficiency regulations, and environmental factors.

Step 1: Determine the application parameters and service coefficient (fs)

Firstly, clarify the required output torque (Mr2), output speed (n2), daily working hours, and number of starts per hour (Z) for the application. Then, the load type (K1 uniform load, K2 moderate impact, K3 heavy impact) is determined by calculating the acceleration coefficient (K) of the load. Retrieve the service factor (fs) from the chart provided in the product catalog based on the K value and the number of startups per hour.

Step 2: Calculate the required power and select the motor

Calculate application demand power (Pr1):

For selecting a reduction motor, first calculate the required input power.

Formula: Pr1=(Mr2 * n2)/(9550 * η d)

Among them, η d is the dynamic efficiency, which needs to be estimated from the efficiency curve chart in the catalog based on the speed ratio (i).

Select motor power (Pn):

The rated power of the selected motor must be greater than or equal to the required power.

Condition: Pn ≥ Pr1