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

Energy efficiency compliance inspection (S1 continuous working system):

For continuous working system (S1), directly select IE2 or IE3 motors that meet Pn ≥ Pr1 and comply with EC 640/2009 regulations.

Non continuous working system (S2, S3,...):

For intermittent working systems (such as S2 short-term operation and S3 periodic operation), the motor can output greater power in a short period of time. This requires the introduction of a power adjustment coefficient fm.

Condition: Pn ≥ (Pr1/fm)

For example, for the S3 working system (cycle factor I=40%), the adjustment factor fm=1.15 means that a motor with a rated power slightly lower than the required power can be selected while still meeting the working requirements.

Step 3: Select the reducer and verify it

Determine the reduction ratio (i): i=n1/n2 (input speed/output speed)

Choose the machine base number for the gearbox:

In the Speed reducer rating charts, find the minimum machine base number that meets the speed ratio (i) requirements and has a rated torque (Mn2) greater than or equal to the calculated torque (Mc2).

Formula: Mc2=Mr2 * fs

Installation position and lubrication:

The VF-W series reducer supports multiple installation methods (B3, B6, B7, B8, V5, V6). Installation must be strictly carried out in accordance with the installation position specified on the order and nameplate. The different installation positions determine the amount of lubricating oil added to the gearbox when it leaves the factory. Please note that the W110 machine base number does not contain lubricating oil when installed in the V5/V6 installation position or when paired with B14 flange motors at the factory, and needs to be refilled by oneself before debugging.

Motor availability check:

Confirm that the interface (flange, shaft extension) between the selected motor and gearbox is geometrically compatible. Bonfiglioli's Motor availability chart provides detailed compatibility guidelines. For example, for the VF 30 frame size, the maximum installed motor power is 0.55 kW.

Temperature management: allowable temperature limits

Temperature is a key factor affecting the lifespan and performance of reducers. The Bonfiglioli catalog specifies temperature limits for different types of lubricants and seals.

Parameter conditions synthetic oil mineral oil

Environmental temperature (ta) Minimum operating temperature -30 ° C -10 ° C

Maximum operating temperature+50 ° C+40 ° C

Surface temperature (ts) Continuous operation maximum temperature+100 ° C+100 ° C

Oil temperature (to) Continuous operation maximum temperature+95 ° C+95 ° C

Key guidance:

If the expected surface temperature is close to the upper limit (such as 80 ° C to 95 ° C), it is recommended to specify a fluororubber oil seal (Option PV) when ordering to ensure the long-term reliability of the seal.

For applications with ambient temperatures below -20 ° C or surface temperatures consistently above 80 ° C, special selection should be made by contacting Bonfiglioli's technical department.

Braking system configuration and selection

For applications that require quick stopping, precise positioning, or safe parking, the VF-W series can be equipped with two high-performance brake motors.

5.1 DC brake motor (FD option)

Working principle: Spring compression, power-off braking. When the coil is energized, a magnetic field is generated to overcome the spring force and release the brake disc; When the power is cut off, the spring pushes the armature to press the brake disc, achieving braking.

Core advantages:

High braking torque: Typically, the braking torque (Mb) is approximately 2 times the rated torque of the motor (Mn).

Adjustable braking torque: can be adjusted by changing the number and type of springs.

Multiple rectifier options:

NB (half wave rectifier): standard configuration.

SB (Half wave rectifier with electronic excitation): Fast response time for brake release, suitable for applications with high start stop frequency.

NBR/SBR (rectifier with quick turn off): A static switch has been added to NB/SB, which can quickly cut off the power supply to the brake when the power is cut off, achieving extremely short braking response time.

5.2 AC brake motor (FA option)

Working principle: Adopting a three-phase AC electromagnetic brake, directly powered by a power source.

Core advantages:

High dynamic performance: very suitable for applications with heavy loads and high start stop frequencies.

Fast response time: with extremely fast brake release and holding time.

Adjustable torque: The stepless braking torque adjustment can be achieved by adjusting the spring pre tightening screw (adjustment range is 30% MbMAX<Mb<MbMAX).

5.3 Brake release and power supply

Manual release: Provides two manual release lever options, R (automatic reset) and RM (lockable in release position), for easy equipment maintenance during power outages.

Independent Power Supply (SA/SD): For special applications, the brake can be powered by an independent power supply to ensure that it can operate as needed even if the motor main power is cut off.