Operating and maintenance handbook Brake motors series CCL

Transcription

1 Operating and maintenance handbook Brake motors series CCL Rev. 01

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3 SAFETY BRAKE SERIES CCL Specifications of the brake series CCL The electromechanic spring brake series CCL is a direct current brake. The purpose of this brake is to stop the rotational movement of a mechanical shaft. To this end, the user has to make sure that the brake is in accordance with his requirements. Only if the required conditions are met, the brake can work correctly. The main specifications of the CCL brake are the following: Very strong structure Very quiet in operating (< 70 dba according to the 98/37/EEC Directive) Economic thanks to a simple assembling of the brake unit Good heat dissipation. This occurs through the motor fan and/or cover that must be made of cast iron or steel as it acts also as a braking surface The electromagnet coil is fully encased with epoxy resin and the mechanical parts are protected by galvanization zinc plating treatment A hand release lever is available on request.

4 Maintenance and repairs It is necessary to frequently inspect all the brake parts as the friction work depends on a number of factors, mainly the load inertia, the motor speed and the operation frequency. Refer to the table operations/hour in order to know the operation times. The replacement of the disc must be carried out considering the following principles: Wear of the disc: the friction material must be replaced earlier if it is submitted to considerable stress due to high working temperatures. The disc must be replaced after a 3 mm. consumption of the friction material. After inspection, make sure that the air gap is correctly adjusted. Inspection must be carried out after having electrically disconnected the brake and after having checked the earthing connection. Proper operation of the brake is guaranteed only if original components supplied by our Company are used. Note: when the air gap reaches a value of 0,7 mm, it is necessary to bring it to its nominal value again.

5 Operation The brake is designed to assure, at rest and by means of the torque springs, the intrinsic safety equal to its nominal value given in Nm. On exciting the electromagnet (1) the armature (2) is attracted towards the electromagnet itself, thus loading the torque springs (3). This enables the disc (4), coupled with the mechanical shaft by means of a toothed hub (5), to turn freely. In case of current cutoff, the magnetic field fails and consequently the torque springs push the armature against the disc, thus braking the mechanical shaft. 1. Electromagnet 2. Armature 3. Torque springs 4. Disc 5. Hub 6. O-ring 7. Ring nut 8. Adjusters 9. Fixing screws

6 Micro switches Brakes provided with microswitch to check movement. The microswitch is adjusted at the factory by the staff in charge for the testing of the unit (motor-brake). By means of the michroswitch it is possible to check the air gap or the opening of the armature. In the first case the microswitch contact normally closed, will open when the armature stroke is ³ 0,7. In the second case, if we want to check the opening of the armature before the motor is moving, the contract of the microswitch will close when the armature is closing on the magnet. If the air gap is > 0,7, the brake might not close and the microswitch warns about the failing of closing. For the adjustment, in the first case bring the armature to its maximum position, loosen the lock nut and by means of the screw that actuates the microswitch, adjust the contact tripping. Close the lock nut. In the second case, electrically close the armature with the magnet, loosen the lock nut and actuate the contact by means of the screw. By means of the screw allow the contact a stroke higher than 0,1 0,15, tighten the lock nut. Check that the contact opens during the armature movement. Repeat this operation in case the contact does not open. Wiring diagram: Normally closed Normally open Common

7 Air gap adjustment Adjustment of the air gap is made acting on the adjusters (8) after loosening the screws (9). If this operation is made at the end of the working time, make sure that the brake body is not overheated. The nominal value of the air gap adjustment is given in the following table with a tolerance of +0,05-0 mm. The maximum value allowed for the air gap is 0,7 mm. If this value is passed due to the consumption of friction material, the performances of the brake may change. Type k1 k2 k3 k4 k5 k6 k7 k7/ D k8 k8/ D k9 k9/ D k9/ T k10 0,2 / 0,6 0,2 / 0,6 0,15 / 0,5 min/max air gap The maximum admissible consumption is 0,5+0/ 0,1, which added to the value of the air gap mentioned above, brings to the maximum air gap value. Overcoming the air gap maximum value leads to a decay of the performances of the brake, until the system does not open during rotation, consequently all brake parts overheat and lead to an unavoidable interruption of the operation.

8 Braking torque adjustment The brake type CCL allows to change the performances of the braking torque. Based the load, the rotation speed and the braking time, the user can set the braking torques most suitable to his working requirements. The table here below shows the distances in mm. of the electromagnet ring nut in order to obtain the requested braking torque. If the load of the work allows it, the adjustment of the braking torque under the 100% value will result in a decrease of the wear of the brake friction material. The graph here below shows this variation, in percentage. The highlighted area delimits the safety value. Type 9mm 8mm 7mm 6mm 5mm 4mm 3mm 2mm 1mm A=0mm Nm Nm Nm Nm Nm Nm Nm Nm Nm Nm K1 0,7 1,4 2,1 2,8 3,5 4,3 5 K2 2 4,5 7 9, K3 2,6 5,3 8 10,6 13,2 16 K K K K K K K7D K8D K9D K9T K K10D Critical area

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