These are used for various applications for Frequent start stop & reversing operations such as Textile machinery, machine tools, printing machines, cranes & hoist.
Brake Motors are used for various applications where instantaneous stopping of the driven load is required. The operation of the brake is “FAIL SAFE TYPE” i.e. normally ON. When the electrical power to the motor is cut–off or the power fails, the brake is applied.
Brake motor is a combination of an A.C. induction motor and an electromagnetic AC or DC brake. The electromagnetic brake is mounted on the non–driving end of the motor.
DC brake motors are provided with a rectifier which provides the required DC voltage to the brake coil which in turn operates the brake. The supply to the rectifier is fed from any two terminals (between any two phases) in the main terminal box of the motor.
General applications of Brake motors are printing machinery, textile machinery, rolling mills, cranes & hoists, material handling equipments, machine tools etc.
When the power to the motor is switched off, a braking torque is generated which presses the armature plate of the brake against the mounting flange. When the supply resumes, a magnetic field is produced in the brake coil and this pulls the armature plate against the spring force and the shaft is now free to rotate.
- The brake motors are simple & rugged & so easy for maintenance.
- No separate DC supply is required as the rectifier is provided which gives the required DC voltage for energisation of the brake.
- The rectifier is mounted inside the main terminal box so no separate terminal box required.
General guidelines for selection of suitable Brake Model:
The Brakes are rated by torque & selection of suitable model can be made by calculating the required torque, rating of the brake & then matching it with static torque.
Torque (Nm) = 9550 x (KW / RPM) x Safety Factor (SF)
where kW-Kilowatts of motor,
RPM-Speed of motor,
SF-Safety Factor depending on type of prime mover & load.
For electric motor, SF = 2 to 3
For diesel engine, SF = 4 to 5
For compressor, SF = 5 to 6.
Brake Coil Connection Diagram:
Brake coil is energized by DC side switching as shown in the diagram.
Hindustan Brake motors can be used in many applications. A few of them are listed below;
- Machine tools
- Textile machinery
- Cranes & hoists
- Printing Machinery
- Material handling equipments
- Geared motors
- Cable reeling drums
- Rolling mills
When placing an enquiry, please furnish the following details;
- Application details
- Motor power & speed
- Brake size / required braking torque
- of start/stops per hour
- Duty cycle
- Selection chart is a general guideline for selection of brake size. If braking torque required is other than that mentioned in selection chart, this can be provided on request.
- Brake motors with safety factor less than 2 are not suitable for crane/hoisting applications.
- Motors up to frame sizes 132M can also be provided in aluminium housings.
- The motor must never be switched “ON” unless brake is energized & the brake should never be de-energized when the motor is “ON”.
- Brake motors with higher braking torque can also be provided on request.