BBL manufactures TEFC three phase DC Brake Motors with Type ‘MB’. These motors are used for applications requiring positive and instantaneous braking. These motors are ‘fail safe’, which means that the brake will be applied immediately in case the power supply fails or is switched off.
These motors have a built in rectifier along with a variator for protecting the rectifier as well as the brake coil from voltage surges. The special brake liner used assures consistent braking torque with minimum wear. This leads to almost maintenance free operation. These motors can be offered in various types of mounting. BBL manufactures these motors in frame sizes from 71 to 132M in 2, 4, 6 and 8 pole.
Multi speed brake motors can also be supplied. Motors from 90S to 132M can also be supplied with a manual release arrangement to manually release the brake.
Being simple and rugged – in construction., these motors need very little maintenance.
No separate DC supply is necessary for brake coil energisation, because a rectifier unit is provided. The rectifier is open type and fixed between the two terminals inside the terminal box. Being open type, it ensures good heat dissipation and is very easy to replace. Varistor is provided across the DC terminals to protect the brake coil and rectifier against line and switching surges.
Special brake liner is used, which ensures that, the braking torque value remains quite stable throughout the use.
Compensation for liner wear is easily done by advancing the position of the fan by tightening the castle nut at the
non-drive end. The design of brake motor facilitates a very easy replacement of armature disc and brake liner assembly.
Since the fan serves as a braking surface (unlike some other designs), it also serves to cool the Brake coil and the motor. These Brake Motors being fan-cooled are available in smaller frame sizes than other brake motors which are surface cooled. Therefore, these motors are more compact and economical for a given application.
For crane and hoist duty application Brake Motors are offered with special rotors. These rotors are specially suited for S3 and S4 duty normally encountered in hoist and crane applications.
Mechanical manual release of the brake as an optional feature is available from 90S to 132M frames. In case of power failure, the brake can be released manually with a lever.