Bonfiglioli BN-BE-BX Series Motor Selection Guide

1. Working principle of FD brake

On page 32 of the manual, it is stated that the FD brake is spring applied and belongs to the fail safe type. When the coil is de energized, the pressure spring pushes the armature plate towards the brake disc, generating frictional torque to achieve braking; When the coil is energized, the electromagnetic force overcomes the spring force to release the brake disc. This design ensures that the brake can automatically engage in emergency situations such as power outages, ensuring safety.

2. Braking torque and heat capacity

Table F34 on page 36 of the manual lists the detailed parameters of different models of FD brakes. When selecting, special attention should be paid to:

Braking torque (Mb): For example, the torque of FD08 is 170-250Nm (adjustable by the number of springs). When selecting, it is necessary to ensure that Mb is at least twice the rated torque of the motor.

Maximum braking power (Wmax): represents the maximum energy (J) that a single braking can withstand. For example, at 100 cycles per hour, the Wmax of FD05 is 500J. If it frequently starts and stops and has a large load inertia, it is necessary to calculate whether the energy of each braking exceeds this limit.

Response time (t ₁, t ₂): Pages 35-37 of the manual compare the effects of different rectifiers (NB/SB/NBR/SBR) on response time. The SBR rectifier achieves rapid demagnetization through electronic switches, and the braking response time (t ₂ c) is significantly shorter than the standard AC power outage (t ₂).

3. Rectifiers and power supply configuration

On page 35 of the manual, four types of rectifiers are distinguished:

NB: Standard half wave rectification, economical type.

SB: Overexcitation rectification - provides high voltage rapid release at the moment of start-up, and then switches to holding voltage, suitable for high-speed response requirements.

NBR/SBR: Equipped with Quick de energizing function and independent braking power supply (SA or SD option) to achieve the fastest braking.

Engineering Tip: If the brake action frequency is extremely high (such as Z0 value approaching the limit in the table), SB or SBR rectifier must be selected, and CF capacitor filter option must be considered to suppress electromagnetic interference (meet EN 61000-6-3).

Hidden details of installation methods and mechanical interfaces

1. Special purpose of B5R "recessed flange"

On page 16 of the manual, a special flange execution method called B5R is mentioned. Its characteristics are short shaft expansion and contraction, and inward contraction of flange stop. This design is mainly used to match Bonfiglioli's own gearbox input flange, in order to achieve a more compact motor gearbox direct connection. The manual clearly warns that the combination of B5R and gearbox must be checked for the maximum input power allowed by the gearbox, as exceeding it may damage the gearbox.

2. Vertical installation (VM option) and rain cover (RC option)

Pages 15 and 52 of the manual emphasize:

For motors with base numbers BX ≥ 200K or BY ≥ 280K, if vertical installation (axis facing downwards) is used, the VM option must be specified because the bearing lubrication and drainage structure of standard horizontally installed motors is not suitable for vertical working conditions.

If installed vertically with the shaft facing downwards, it is recommended to choose an RC Rain Canopy to prevent condensation or splashing water from flowing into the internal bearings of the motor along the shaft.

3. Junction box and cable entry

Table F11 on page 18 of the manual provides a detailed list of cable entry specifications for junction boxes with different machine base numbers. For example, BX 160 (machine base 160) is equipped with 2 M40x1.5 and 2 M20x1.5 threaded holes, with a maximum allowable cable diameter of 28mm and 13mm, respectively. During the project design phase, if large section cables or servo cables with thick shielding layers are used, this size limit must be reviewed, otherwise an additional IC option (additional cable entry) needs to be selected.

Special considerations for inverter duty

The 30th page of the manual specifically discusses the precautions for inverter power supply.

1. Insulation system withstand voltage

The standard BX/BE motor adopts F-class insulation, but for the high-frequency pulse voltage (dV/dt) output by the frequency converter, its insulation system has a withstand voltage capability of 1600V peak to peak, and no additional output filter is required when the rising edge time t_r>0.1 μ s. This is Bonfiglioli's standard design guarantee, but if long cables (>50m) are used or the supply voltage is higher than 500V, it is recommended to contact the technical team to evaluate whether a sine wave filter needs to be installed.

2. Speed range and constant power range

When variable frequency speed regulation is used, the motor is in the constant torque range below the fundamental frequency (50Hz); Above the fundamental frequency is the constant power range (torque according to)

one/f The 1/f ratio decreases. On page 30 of the manual, the mechanical limit speed for each machine base is provided: for example, BX 132 allows a maximum of 4500 min ⁻¹, while BX 280K only allows 2000 min ⁻¹. If high-speed operation is required, the dynamic balance level must be checked, and if necessary, the RV (Balance Level B) option can be selected to reduce vibration.