POWER DRIVES (GUJ.) PVT. LTD. Makarpura, Vadodara, Gujarat

High resistance motors popularly known as torque motors are used mainly for winding application. Plastic blow film Extruders, redrawing and coating of copper and other wires, plastic and cotton strip and rope winders are few applications. “mototek” torque motors are designed to operate from quite a long strall time and with addition servo type cooling for reliable and long operation. “mototek” torque motors are available in different RPMs to suit the application. For bigger winder torque geared motor with servo type cooling are also manufactured.

Machine Tools and Process industries do need variable speed motors to either achieve desired machine function or for energy conservation. Application like fan and certrifugal pumps are an excellent example of energy saving through VFD. VFD or Frequency Inverter is not a new word for the industry now. "mototek" Inverted rated motors are suitable to operate with VFDs.   The motors are insulated to withstand the voltage spikes generated while working with VFDs.   Depending upon the required operating speed range and close loop feed back for automation motors can be selected.   (A) Where speed of the motor is to be reduced approximately up to 50% of the rated speed, than the integral fan on the motor shaft is sufficient to provide enough cooling. It again depends on the type of load. If the load is of fan or centrifugal pump type, than motor with integral fan can go even further low speed at the same type heavy duty load with intermittent increasing load application may need extra cooling. This is just a guideline to understand the basic requirement of cooling.   (B) Where the speed of the motor is to be reduced further the integral fan mounted on the motor shaft becomes inactive OR when the speed of the motor is to be increased with a frequency above 60 Hz. The integral fan overloads the motor. ln such situation, it becomes very important to provide extra cooling by separately energized fan i.e. servo ventilation (lC 46 cooling). Servo ventilation (lC 46 cooling) is available from the frame 71 to 280. For smaller frames, it is recommended to use higher frame, if B5 flange mounting than reduced flange can also be used.   (C) The automation requirements are increasing day by day and it is becoming important to control the speed of the motor or position of the motor shaft for positioning and synchronizing requirement of machine tools and process. "mototek" motors with servo ventilation as well as normal fan cooled are available with either incremental encoders, absolute encoders and resolvers of various supply and output. As a standard "mototek" can offer quick delivery with 1024 PPR - 10 to 30V DC Push- Pull incremental encoders.   Servo ventilated motors, motors with encoders or both are longer compared to standard motors. If the space is the craitaria, please confirm the length before ordering.

Many application such as special purpose gearboxes, non continuous operating machines or motors having radial & axial loads need flanges smaller or larger or larger than the standard frame.   “mototek” motor are available with such flange.

Many application in industry needs dual speed motors. The motors work on either of the speed as selected. The speed change can be achieved by separate winding of the motor or by changing the pole connections. By and large the output torque of the motors remains same in both speed and hence the power of the motor changes with respect to speed. Application of dual speed motors are endless, to name a few “mototek” dual speed motors are being used for hoisting , positioning application for precious positioning and avoid jurking, centrifugal fan or pumps for energy saving, machine tools for batter size control and special tooling operations.

When overall optimum performance is targeted, customization is must for any process or machines, so the motors “mototek” has developed and keen to develop customized motors. Customization for mechanical as well as electrical requirements can be developed and manufactured. It could be for vibratory applications, stirrer applications, positioning and many such applications, “motoek” custom built motors proves to be best value for money. Faster conceptualization to development and to production is the biggest strength of team “mototek”. It is a total team effort of electrical design, mechanical design and production team.   Motors with extended shaft, hollow shaft, special flanges, special foot mounting along with special power ratings, frequency, voltages, jacketed cooling and many such combinations are designed and developed by “mototek”.

Many processes generates excess heat which is cooled by cooled water. The heated water is cooled by cooling towers. The motors for fan of cooling tower works under harsh conditions, the ambient temperature is quite high and highly moist surrounding. “mototek” cooling tower motors are protected with IP55 enclosure protection to minimize the entry of moisture inside the main motor body and terminal box. Efficiency and cooling are batter to withstand the higher ambient temperature. Being under continuous and loaded operation, energy saving is must. It is recommended to use higher efficiency motor for cooling tower. Bearing used are of rubber shield and for better radial loads, to ensure the efficient operation with longer life and minimum friction.

Brake motors are required when you want the motor to stop quickly even with heavy inertia/load like hoisting, positioning or material movement. "mototek" brake motors are becoming popular due to its practically maintenance free and noise less performance. "mototek" Brake motors are normally supplied with D.C. fail safe brakes, also known as normally ON brake. The motor is braked (Locked) when power is not applied i.e. de-energized to brake. This ensures real fail safe braking. The construction is quite robust and requires very limited maintenance. With wearing of liners on the rotor of brake, the air-gap can be easily adjusted. lf necessary, the rotor can be easily replaced completely as well. The brake is mounted on end covers on non-driving end of the motor. lt comes with a Manual release lever.   Selection Criteria It is recommended to use proper size of brake. It should not be undersized or should not be over sized as well. Depending uponthe application, the service factor of the brake has to be selected for proper braking. Service factors for selection for the brake are mentioned in the selection table. This is just a guideline as there are many other factors to be considered while selecting the brake size like mounting positions, type of transmission and type and ratio of reductions. We request you to consult "mototek" for proper selection of brake size.   SUPPLY     Unless otherwise specified, brake voltages are 190 V DC with a rectifier of 415V A.C. dual phase input and 190V DC output duly fitted on the motor and properly connected with the terminals. For faster brake releasing action, 96 V D.C. brakes can be used with the some rectifier.-but with an input supply of 230V AC. Brakes with 24V or 48 V DC can be supplied but without rectifier. For these supply voltages brake, inbuilt rectifier is not available. Hence the brake has to be energized and de-energized external supply and controls.   SWITGHING Motors are connected with AC switching as standard. For faster action i.e. reduction in the delay time in operation, DC switching can be used. Care must be taken while DC switching as it generates heavy sparking across the making and braking contacts which can lead to shorting of switching contacts and ultimately leads to failure of contact making or braking. This may become a cause of accident in some cases. Hence suitable universal shock suppressors and capacitors can be used which are normally not included in the "mototek" motors. Fast acting rectifiers are also available as well. Alternatively, 3 phase AC brakes can be used as well.   AIR-GAP ADJUSTMENT The air gap between the armature of the brake and the plates is important as the braking torque and engage and disengage time of the brake. lt is recommended to verify and if required to adjust the air-gap periodically for consistent performance. It will not only improve the braking performance but will also increase the life of liner. The Brake is mounted on the rear end cover of the motor with three to six ellen bolts "L" near the outer periphery of the brake as indicated n the figure. These ellen bolts “L'' pass through hollow hex bolts "H" which are in the opposite direction of the ellen bolts "L". Moving plate "M" is located between the armature and brake coil housing which moves axially during operation of engaging and disengaging. The air gap between this moving plate "M" and brake coil housing has to be maintained. It can be measured with a filler gauge or any other suitable measuring system. To set the air gap, loosen all the ellen bolts "L" and unscrew all the hollow hex bolts "H" slightly to increase air gap and tighten them to reduce the air gap. Tighten the ellen bolts "L" and measure the air gap near the bolts if required adjust the air gap again to achieve specified air gap as mentioned in the table.   OPTIONS AC fail safe brakes and Normally off (energized to brake) brakes in different operating voltage can be supplied subject to confirmation. Motors with shaft extensions on rear side can be supplied if required for manual operation. A small handle can also be provided.   LENGTH OF BRAKE MOTORS Dimensions of the brake motors are same except the total length. Length will be longer than the standard motors. Tentatively it will be as indicated in the table for motors with DC or AC fail safe brakes. For other types of brakes, please confirm the same.