What Is a Magnetic Clutch?

An electromagnetic clutch is a friction clutch that generates a pressing force by electromagnetic force. Because it can achieve long-distance operation, the control energy is small, and it is convenient to realize the automation of machine tools. At the same time, it has fast movement and simple structure, and has also been widely used.

Electromagnetic clutch is also called electromagnetic coupling. It is an electromagnetic mechanical connection that uses the principle of electromagnetic induction and the friction between the internal and external friction plates to make two rotating parts in a mechanical transmission system. The driven part can be combined with or separated from it without stopping the driving part. Device is an automatic electrical appliance. The electromagnetic clutch can be used to control the starting, reverse, speed regulation and braking of machinery. It has a simple structure, fast action, small control energy, and is convenient for remote control. Although small in size, it can transmit large torque. When used as brake control, it has the advantages of rapid and smooth braking, so the electromagnetic clutch is widely used. It is widely used in various processing machines and mechanical transmission systems.

The role of the electromagnetic clutch is to transmit the torque (or power) of the actuator from the driving shaft side to the driven shaft side. It is widely used in various mechanisms (such as transmission mechanisms in machine tools and various electric mechanisms, etc.) to achieve functions such as quick start, braking, forward and reverse or speed regulation. Because the electromagnetic clutch is easy to realize long-distance control, and it is much simpler to operate than other mechanical, hydraulic or pneumatic clutches, it is an important element in the automatic control system. ^[1]

1. High-speed response: Because it is a dry type, the torque is transmitted quickly, and convenient movement can be achieved.

2, strong durability: good heat dissipation, and the use of advanced materials, even for high frequency, high energy use, very durable.

3. Easy to assemble and maintain: belongs to the ball bearing

There are two types of electromagnetic clutches: fixed coil type and rotating coil type. The former is fixed on the compressor casing and does not rotate, and the latter is connected with the reel to rotate.

(1) Fixed coil clutch

The electromagnetic coil is installed on the end cover of the compressor and does not rotate. The rotor is held on the electromagnetic coil by the bearing and the spring. The outer part of the rotor is a reel. An armature (clutch plate) is mounted on the end of the compressor crankshaft. The fixed coil electromagnetic clutch is mainly composed of a pulley, an electromagnetic coil, a pressure plate,

1. Please use the dry electromagnetic clutch without any moisture, oil, etc., if the friction parts are contaminated with moisture or oil, etc.

Quality, the friction torque will be greatly reduced, and the sensitivity of the clutch will also be deteriorated. In order to avoid these situations in use, please add a cover.

2. When using in a dusty place, please use a protective cover.

3. Please use the specifications of JIS0401 H6 or JS6 for the length of the long shaft used to install the clutch. Use one of the keys for mounting the shaft as specified in JIS B1301-1959.

4. Considering thermal expansion and other factors, please select the thrust of the mounting shaft below 0.2MM.

5. When installing, please adjust the suction gap to within plus or minus 20% of the specified value on the machine.

6, please keep the bracket light, do not use clutch bearings to bear excessive pressure.

7. For screws for assembly, please use spring metal sheet, adhesive, etc. to prevent loosening.

8. While the lead is maintained by the frame on the machine side, it is also necessary to make a reliable connection by using a terminal board and the like.

1. Connecting and disconnecting action: If the drive part is installed between the starting part and the starting part, it is not necessary to stop the driving part. The starting part will perform the connecting and disconnecting action according to the necessary response.

2. Speed change: There is a case where the speed is switched between each other during the operation. When the clutch is used at this time, the speed can be changed without closing the drive.

3. Forward and reverse rotation: When the forward and reverse rotation of the load point is switched, it only needs to rotate in the forward direction when used with the clutch.

4. High-frequency operation: Intermittent operation in fast cycles, repeated use of ON and OFF on the motor provides limited frequency, so use the clutch to make it respond quickly and brake with high precision.

5. Inching: When the machine starts to engage with the position, it only needs to act on the clutch momentarily.

In order to ensure the uninterrupted operation of the electromagnetic clutch, it must be maintained and maintained frequently:

1. Lubricant is often added to the movable part of the electromagnetic clutch.

2. Regularly check the length of the armature stroke. Because during the operation of the clutch, the stroke length of the armature will increase due to the wear of the profile. When the armature stroke length does not reach the normal value, it must be adjusted to restore the minimum gap between the braking surface and the turntable. If the armature stroke length increases above normal, suction may be greatly reduced.

3. If the worn brake surface is replaced, the minimum clearance between the brake surface and the turntable should be readjusted appropriately.

4. Frequently check the tightness of the bolts, especially tightening

1) As the engagement and disengagement of the electromagnetic clutch is performed at a high speed, there will be many marks on the surface of the iron plate and the rotor. These traces are not harmful to work and are allowed.

2) Appropriate voltage is applied to the electromagnetic coil. For a 12V voltage solenoid, if it is added to a 6V voltage system, it cannot generate a sufficient magnetic field, which will cause the iron to slip, shorten the clutch life, and reduce the cooling capacity. Conversely, if a 6V coil is added to a 12V system, the coil life will be shortened.

3) The gap between the coil and the rotor is very important. The coil and the rotor should be as close as possible in order to obtain a stronger magnetic field.

4) The gap between the rotor and the suction iron is also important. If the gap is too small, when the clutch is disengaged, the rotor will drag the suction iron. But if the clearance is too large, there will be too little contact between them when the clutch is operating. Both of these conditions can cause poor clutch performance. The reasonable gap between them should be that when the clutch is without current, the two do not drag; when the clutch is current, it can ensure that no slip occurs. ^[3]